That's actually a pretty decent idea.  Or a variation -- instead of paying out coins for your change, that amount just gets an electronic debit into an account that acts like (or is linked to) a prepaid debit card.  Since it is going from the merchant to the customer, there's no pin # or anything else needed from the customer -- just their magstripe card or QR code, or even just a phone number.  I wouldn't be surprised if something like this already exists.

Merchants would love it because it can now tie customers that pay cash even to its customer database / analytics / data mining systems.  And that's were my interest in seeing this succeed ends.

It isn't just having a miner that will accept zero-fee that is a factor here.  

The bitcoin software run by the nodes specifically will, by design, refuse to relay these tiny, zero-fee transactions.  So even if there is a miner willing to include them the miner will never know of them as they were never relayed by the peers.  (there is one exception -- if the client doing the spend knows the IP address(es) of miners that will accept these zero-fee transactions the client can be configured to explicitly connect to these miners.)

So let's go back to the very first part of this thread -- the title:
  "i thought transaction fees are optional?"

The correct response is:
  "You thought wrong, sorry."

If you don't find anyone here, you might want to try on Ogrr:
 - https://ogrr.com/

Is this in the U.S.?  Are you not aware of Dwolla?  $0.25 per transaction.  Takes about a week to get set up initially but from there it is pretty quick.


Well, wire transfers are insanely expensive for amounts in the range you are describing (e.g., $50).  If the transaction did complete, your $50 that reached your credit union would likely have seen an incoming wire fee as well, leaving you with just $35 perhaps.

Anyway, from here, what you should do is open a ticket and ask if there has been a change in status.   If there was an invalid account number, then Mt. Gox got the $50 back and maybe there are fees that would explain the transaction you see. 

To open a ticket:
  - https://support.mtgox.com/anonymous_requests/new

If you need your money quickly, probably the best option to date is to buy a MoneyPak to load a prepaid debit card that can be used to withdraw at an ATM.  That's not cheap, but it is quick. 

In the U.S. though, withdrawing through Dwolla works pretty slick.

TradeHill's site is down but they are going to reopen it to allow for further withdrawal requests, per Jered of TradeHill:
 - http://bitcointalk.org/index.php?topic=67284.msg788927#msg788927

He does offer to handle via e-mail:
 

The amounts are irrelevant.  This is because bitcoin fees are based on the size of the data that make up the transaction and not the amount of bitcoins spent in the transaction.  

Take the transactions from the Bitcoin Faucet for example.  That is an example of a microtransactions-based service running today.  Those payments are sent out in batches.  The 0.0005 fee is paid per batch so the actual fee for each recipient from the faucet is a fraction of 0.0005 BTC.  Sendmany makes it possible for the fee to be trivial even for microtransactions.


Yup -- that scenario is one that Bitcoin, a decentralized ledger system, does not serve.  Though if you have a service that handles those micro transactions internally (denominated in bitcoins or something backed by bitcoins even) and only sends to and receives from the blockchain the deposits and withdrawals for its customers, then you can do that and is something well served by Bitcoin.

None of the charts are working at the moment.

e.g.:
  - https://blockchain.info/charts/n-transactions

And from back in September, incidentally.  But I hadn't seen that listed here yet, so good post!

Update on that calculation since we are exactly nine months from the target date on the bet:
 - http://betsofbitco.in/item?id=312

With block height of 170,390 reached, doing the math that gives us 275 days left, so still on target for December 9th as the day block 210,000 will be reached.

What is certain is that the number of bitcoins issued each day will be cut in half.  Meaning if miners are generating $36K worth of bitcoins on December 8th, then the drop occurs, then starting on December 9th they will generate $18K worth of bitcoins -- though there would be some fluctuations in price that might cause those numbers to vary but essentially it will be a sudden 50%-ish drop in revenue.

We know today within a window of a couple weeks when that event will happen.  We also know miners who pay for electricity won't mine at a loss for very long.   We also know many miners have no other use for the GPUs.

A rational miner might consider selling off those GPUs before there is a glut on the market (though prices have dropped for used GPUs, prices currently are pretty decent -- compared to the discount other electronics see when being sold as used.)  A rational miner might also look at the emergence of FPGAs in mining combined with this 50 BTC -> 25 BTC block reward drop, see the writing on the wall, and start taking action now.

Which would cause a rational speculator (if there are any) to suspect that difficulty will not continue rising and instead will start dropping again as the result of miners shutting down, and thus the date occurring later than December 9th.

But then we have history.  When difficulty goes up, it tends to do so in bursts -- 8%, 15% or higher even.  When it drops, it does so gradually.  Which would mean even if we reach block 210,000 and the difficulty is no higher or lower than the level it is at today, we'll get there sooner than December 9th because the bursts had a bigger impact on calendar time than the drops did.

I still have no leaning as to which outcome is more likely.  Tell me what the exchange rate will be and the number of FPGA units that will be sold over the next half year and the difficulty level at a future date becomes easier to predict.

 - Prepaid mobile phone cards (e.g., T-mobile pay-as-you-go cards, w/ scratch-off code so can redeem online).

In about nine months the block reward is going to drop to 25 BTC (about 3,600 per day).  Let's say that for whatever reason, by that time the exchange rate is about double it rises to $10.  Then it stays at that level for a year.

So that is $36K USD "issued" per day.  365 days/year = $13.1 million for the year of gross revenue for mining.  I'm speculating here, but since competition is global and there is a low barrier of entry, mining profitability (margins) won't get much more than 30%.  So you are talking about $3 million of profits occurring for all Bitcoin mining occuring in the entire world.  I really can't imagine a single large entity even letting thoughts wander towards bitcoin mining.  Particularly not either JP Morgue or the squid.

Well, be careful when taking shortcuts though.  For instance, using BlockExplorer.com's HTML to get the list of tickets.  There is no guarantee that BlockExplorer is truly representing the blockchain.  The operator of it is trustworthy but what if the site is compromised somehow -- an attacker could manipulate the response page(s) to cause the wrong ticket to appear as the winner.  At some point, BitLottto's jackpot becomes tempting for a hacker.

The only way the bank could do a debit / "charge" to Jimmy to spend his bitcoins would be to have a copy of the private keys from Jimmy's wallet.  So this is essentially no different than jimmy depositing his bitcoins with the bank in advance.  Which is exactly how the prepaid debit cards from AurumXChange and OKPay operate today.  Except that the conversion to USD occurs at the time the funds are "deposited" to the prepaid card, and not deferred until the USDs are spent from the card.

Now instead if what you are describing is that the bank sends a monthly statement to Jimmy who is then obligated to send payment for the charges plus fee well then that is a credit card, not a debit card.   And reportedly, AurumXChange is going to allow that to happen as well (allow you to send bitcoins and have those converted to USDs to be applied as payments to the balance on your existing credit card or your debit card used with your bank even.)

Perhaps if it were to show the history for the address that you are sending to.  Feedback such as ...
 Your transfers to this address:  Qty: nnn  Last transfer:  nn/nn/nn

though maybe that would be an advanced mode or only something that appears if you're sending larger amounts?

But the real problem is people re-using addresses.  The address for sending to Mt. Gox should not be what you see from a label in your own wallet from a previous transaction but from the address just created for you from Mt. Gox's site.  That's the proper method.  Especially for a transaction amount in the 73 BTC range!

Doh!  The PowerBall draw is not the same as Mega Ball draw.  Wow -- shows you how much interest I have in the State-run lottery.


Isn't that correct?  The details from the site reads:

- http://bitlotto.com/details.html

So in that example above [with the wrong Mega Million picks], there were multiple hashes that tied on the first pick (6), but to settle that tie, the next pick was used (0) and there were no further ties.  Is that the correct methodology?

----------------------------

So, to do that winner selection over, using the correct Mega Millions lottery picks this time.

Determine the lucky block (first block after the deadline): 169953
 - https://blockexplorer.com/b/169953

Hash from that block:
 00000000000005300076544c21d2f352480c1efb4c1cec75125223f66a7015be

Add to that hash the Mega Millions picks:
20 24 31 33 36 Mega Ball 44
 - http://www.powerball.com/megamillions/mm_numbers.asp

Append the picks to the block hash and you get:
 00000000000005300076544c21d2f352480c1efb4c1cec75125223f66a7015be202431333644

Get the sha256()
 ee4cea6ea146419c874279bce52be30159b11709915d19efecd94a9a1a3f4222
 - http://www.xorbin.com/tools/sha256-hash-calculator

The Winning Picks are the first ten from that hash:
 ee4cea6ea1

Create the work file.  The address for the March draw was: 1CdGqgJegokVaW5tPgC2vy3dZciggARdmh
 $ GET http://blockexplorer.com/address/1CdGqgJegokVaW5tPgC2vy3dZciggARdmh|grep "/tx/"|cut -d " " -f 3|cut -b 11-74 > workfile
 (This grabs the HTML source for all the tickets for the monthly draw address, then cuts away everything but the transaction hashes.)

Remove from workfile any transaction hashes that were disqualified (e.g., entered late, amount was not large enough, etc.)

Determine the longest of the picks where there is at least one match:
 $ grep e workfile|wc -l
 $ grep ee workfile||wc -l
 $ grep ee4 workfile|wc -l
 $ grep ee4c workfile|wc -l

There were no transactoin hashes that had ee4c, so the winning pick is one of the ones with ee4.
 $ grep ee4 workfile|awk 'BEGIN {FS = "e"};{print $0 " " NF-1}'|awk 'BEGIN {FS = "e"};{print $0 " " NF-1}'|awk 'BEGIN {FS = "4"};{print $0 " " NF-1}'|sort -rk2

This results in:

e1401f846cff82658f354fbed814ee414deb2fed461eed8c0e4dd3d8fa49d841 9 9 10
4e1c5454c7f13b66b39f162ec22fdd3d949d5f406e80ee4f6b07ea055906f821 6 6 6
e15ddfbf7a0ab05840f630427c1d18b6d680cfc443defd3c86ecbf87eee49a91 6 6 5
6e0c6874fc4ba9c55fbc269829e6868f058f6249a5249b8ed8ee490b8407699f 5 5 6
5677bf49d4595ca999dd2322732e64530d29b8b2eb76ef14f877520ee45f8dac 5 5 5
70141509656d93ee42651929c29fb9e65318474e02a01fc99cb6783262ffc2a3 4 4 6
f88e31a5e1f57330f384381926c5294553a31b90850925bc6ba6ff83951aee43 4 4 5

There was just one hash that had the most "e"s in it (9) -- so there were no ties.

If there had been, that tie would be broken by performing the same test for the next pick.  Since in this months lotto, the second pick was the same as the first so we would still have a tie so would then move onto the next pick -- in this case, "4".  If that pick too had resulted in a tie then the test would be done using next pick after that, in this case the "c", and so on until either there are no ties or until all ten picks have been used in the tests.  

So at this point, the one entry becomes the winner:
 e1401f846cff82658f354fbed814ee414deb2fed461eed8c0e4dd3d8fa49d841

That is the winning transaction. Looking at that transaction:
  2012-03-06 07:19:02
 - http://blockexplorer.com/tx/e1401f846cff82658f354fbed814ee414deb2fed461eed8c0e4dd3d8fa49d841

There is one one input to that, so that is where the jackpot will be sent:
 1Nb2W2F56kuZeKAAhyEAbTomfn3RPt4t2D

This [unofficial] result jives with the unofficial result posted by bitlotto earlier.

In the U.S. one of the methods gaining wide use is the ability to deposit cash at a bank and get a redeemable code usable at any exchange that issues those codes.   The fees are relatively small (under 4%).   I've seen mention that this type of cash-deposit service is likely going to be available in Europe (depositing EURs) as well, soon (though whether that means days, weeks or months I don't know.)


There are plenty of options for SEPA bank transfer.  Do all of them incur fees that are unacceptable?:
 - http://en.bitcoin.it/wiki/Buying_bitcoins

Are you referring to a card that has bitcoins stored on the card itself?  Because of the nature of bitcoin, that concept doesn't work -- you need a device to manage the security and facilitate transactions -- and that is something solved with a mobile device.  See BitcoinSpinner on Android as an example.

Or are you referring to a system where the card is simply a credential that will let you spend bitcoins from a bank service.   This has been proposed but because bitcoin is meant to be a a decentralized currency, this approach has few fans to date.  It would also require the merchant to acquire a card swiper that the customer would use to enter a PIN or an NFC terminal or something.  Nobody is working on this, at least not that they are publicly discussing.  Online, of course, this "debit card" concept doesn't apply, and is served by users with a bitcoin client, an online wallet or through payment processing such as that offered by Bit-Pay, Mt. Gox.

One category of a debit card is a USD-denominated physical Visa/MC cards (sent via mail) for making purchases at any merchant but where the cards can be purchased with bitcoins.

The follow are purchased and reloadable with bitcoins:
 - https://www.aurumxchange.com/cards
 - https://www.okpay.com/en/services/debit-card

There are others but I'm not listing them here as I don't know much or anything about them.  They might be found here:
 - https://en.bitcoin.it/wiki/Trade#Gift.2FDebit_Cards
 - https://en.bitcoin.it/wiki/Trade#Gift_Cards

As far as purchasing other USD-denominated cards, there are different categories of that as well:

Virtual, prepaid gift codes (purchased and order fulfilled entirely, online)
 - http://www.spendbitcoins.com (Amazon, Barnes & Noble, GoDaddy, Southwest Air)
 - http://coincard.ndrix.com (Amazon, Best Buy, Dominos, Papa Johns)
 - http://www.btcbuy.info (Amazon, Think Geek, Sears, NewEgg, Drugstore.com)
 - http://www.btcinstant.com (Virtual Mastercard)

Physical gift cards (via mail):
 - http://coincard.com  (new, appears to have site issues currently)

Any there are many prepaid debit cards that can be reloaded with a MoneyPak (e.g. Green Dot, WalMart, AmEx or dozens of others listed here https://www.moneypak.com/WhoAccepts.aspx ).  

You can buy new MoneyPaks here:
 - http://www.btcpak.com

There is even a service for buying bitcoins using your Visa/MC/Amex prepaid debit card:
 - http://www.Get-Bitcoin.com

If you notice, there is lots of need yet unfulfilled.

How about prepaid mobile phone service?   e.g., T-Mobile prepaid cards?  
These can be bought wholesale (e.g., at a discount) and then can probably be sold at a premium even.  But nobody is offering this, at least not in the U.S.  In Thailand, BhatCoin is selling phone cards for Bitcoins.

Or even direct competition with an existing service -- there could be a market to support more yet.

Oh man, that's gonna leave a mark.

Sorry to hear this.

If it helps -- thus far it hasn't been spent:
 - http://blockexplorer.com/address/1w2giXiGAHiFnjyUyVyMubszKRQb8MEYt

Perhaps Meni can assist?
 - http://bitcointalk.org/index.php?topic=5762.0

I don't have it automated but I've used this method to verify the winner before:

Determine the lucky block (first block after the deadline): 169953
 - https://blockexplorer.com/b/169953

Hash from that block:
 00000000000005300076544c21d2f352480c1efb4c1cec75125223f66a7015be

Add to that the Mega Millions PowerBall number:
12 35 45 46 47 Mega Ball 12
 - http://www.powerball.com  


[Update: Ooops, MegaMillions picks != PowerBall picks]  all the results I had posted following that are thus invalid.  The correct URL for Mega Millions is:
 - http://www.powerball.com/megamillions/mm_numbers.asp
]

Add those together:
 00000000000005300076544c21d2f352480c1efb4c1cec75125223f66a7015be123545464712

Get the sha256()
 6055a779449804c1a4151c2c61addc5143ba498105c197a2ba8c3a170c03316d
- http://www.xorbin.com/tools/sha256-hash-calculator

The Winning Picks are the first ten from that hash:
  6055a77944

Create the work file.  The address for the March draw was: 1CdGqgJegokVaW5tPgC2vy3dZciggARdmh
 $ GET http://blockexplorer.com/address/1CdGqgJegokVaW5tPgC2vy3dZciggARdmh|grep "/tx/"|cut -d " " -f 3|cut -b 11-74 > workfile
 (This grabs the HTML source for all the tickets for the monthly draw address, then cuts away everything but the transaction hashes.)

Remove from workfile any transaction hashes that were disqualified (e.g., entered late, amount was not large enough, etc.)

Determine the longest of the picks where there is at least one match:
 $ grep 6|wc -l  
 $ grep 60|wc -l
 $ grep 605|wc -l
 $ grep 6055|wc -l

There were no transactoin hashes that had 6055, so the winning pick is one of the ones with 605.
 $ grep 605 workfile|awk 'BEGIN {FS = "6"};{print $0 " " NF-1}'|awk 'BEGIN {FS = "0"};{print $0 " " NF-1}'|awk 'BEGIN {FS = "5"};{print $0 " " NF-1}'|sort -rk2

This results in:

a247d96ebcd90bda3f27f8824a98026c086d0da89dd60ba3d26a3954299605d7 6 6 2
17554f9d7de77f067fa6f709155adc4ad60560ca2180b2364d456123192b18f2 6 5 7
72d83f262660589f79c4b09279ffe717735b8f631a83c9413ac1a36a490307e6 6 4 2
5b6a443d317f623c16e7e3f4369bd093d560579dfda4c728d4179ffbfb228651 6 2 4
352c6fc98f21a036a74d12100a838605a5bb0fc7534b1fd6bd9a790f1b8dd976 5 6 5
ca61a3e84def3f879275b07bd41605a340317727948daa095e8555447af66a63 5 4 7
be7ac025e74874cde49640f0d035a2d9465ee1b89700605de8334765cd8f1fe4 4 7 5
98bc4fa7153f2627430210c99605d24c110aad0152834f60c5638713d7324904 4 7 4
ef8605feef9240b75039eb5f975db52a49d8a305138c5f422c22af63e1469e25 3 4 8
b7ec93b1440e21e605b479f36d8f72df89423a24c768709c31880ea49d79d94d 3 4 1

There are multiple hashes that have six "6"s in them, so there are ties.
That tie is broken by looking at how many "0"s there are.  There is one that has more "0"s than any other, so the tie is broken and we have the March winner:
 a247d96ebcd90bda3f27f8824a98026c086d0da89dd60ba3d26a3954299605d7

That is the winning transaction. Looking at that transaction:
  2012-02-21 00:19:18
 - http://blockexplorer.com/tx/a247d96ebcd90bda3f27f8824a98026c086d0da89dd60ba3d26a3954299605d7

There is one one input to that, so that is where the jackpot will be sent:
 1FiJ55znEC14bd4xnoX32jnKus6BUGQstn
 - http://blockexplorer.com/address/1FiJ55znEC14bd4xnoX32jnKus6BUGQstn

**************

Now ... these are unofficial, possibly flawed results.  Don't chuck your wallet if it looks like you lost and don't go nuts ordering new GPUs if it looks like you won!