Bitcoin Forum

https://i.imgur.com/70neLG2.gif (http://spinjar.me/preview)

"Spinjar is a Bitcoin donation address that gives users the chance to win with every donation." (http://spinjar.me/preview)

A few months ago Josh Rossi (of Satoshi Square (http://letstalkbitcoin.com/satoshi-square-an-homage-to-wall-st/) fame) suggested that it might be possible to incentivize donation and charitable giving, by creating special addresses which automatically enter part of any Bitcoin sent there into a simple lottery. We lovingly refer to this as "the Satoshi Dicing of everything".

There's a famous book suggesting one should consider productizing one's development byproducts. As it happened, the requirements for an absolutely minimal implementation of Spinjar manifested along the path of learning some new tools, thus we have this to share:

http://www.spinjar.me/preview

As far as we know, Spinjar is the first implementation of such an idea. And though the addresses listed work, this is only a proof-of-concept, and has several drawbacks: The winning odds aren't great, we are not sure how to handle minuscule donations, and, at least for the time being, we need to generate Spinjar addresses by hand.

We would like some feedback on the concept: Would you use this -- why or why not? How could we make it better? Provided a little bit of idea validation, we'll continue the development openly and push out an easy-to-embed widget like this:

https://i.imgur.com/L37Zq33.png
https://i.imgur.com/zi4cOzT.png

If anyone here wants a Spinjar address, please email me:

connect@humint.is

Thanks for your consideration!

Interesting idea and it makes a change to be shown an idea with some real thought behind it as well as a nice clear site.

 I personally don't know how I feel about incentivised donations but good luck to you and I'm sure the idea will take off. My only question is whether it would increase donations or is just a nice side product to donations you would send anyway.

Indeed, and I'm not sure if this proof-of-concept will answer the question either, since there are literally countless ways to tweak it. Josh suggested that we need to make the whole process more socially engaging, so we'll think about that. If you or others have suggestions, we are all ears. If we can prove some model that really does increase donations on the whole, it will be a win for everyone.

Thanks for the feedback!

Well you have a great start with this idea! Gamifying the donation's process as an incentive is the way to go and providing a lottery on top of an address  is simple and elegant. But to be more "socially engaging" the users must have an incentive to "collaborate" to achieve some goals and so sharing the offer as much as possible. For this i think a great way is to provide the donation process as a mean to unlock the access of a bonus content that is unlocked when a threshold amount is reached. This can be as simple as a widget with a progress-bar and a qr-code to accept donations, when the goal is reached the progress-bar is replaced with the link of the desired content.

great idea..

To be clear, we're really talking about two applications of this general paradigm, right? On the one hand, there's the simplest form: a standard tip jar, where the person who created the Spinjar address is simply trying to collect some indeterminate (but maximized) amount of funds. And on the other hand, there's a crowdfunding/Kickstarter-esque approach with a monetary (or content) kickback incentive. I think that both of these ideas are interesting and valid, and certainly possible to do under this framework.

By the way, we received a few PMs requesting them, so I should say it here: If anyone wants a Spinjar address to test out, just email me...

connect@humint.is

For the provably fair chance pool. When it give money and when the winner are choose ?

The probability to win is a bit below 1% or in other words statistically every 100th donation wins. Otherwise you get a confirmation amount of 1,111 Satoshis back. If you don't get anything back, please email us, because you found a bug. ;)

https://i.imgur.com/qp63V3l.png

Couple of updates:

Embeddable widgets are now available!
Blog post: Spinjar: Bitcoin vs Ethereum, a Test Case (http://labs.humint.is/spinjar-bitcoin-vs-ethereum-a-test-case/)

Enabled at my music website

http://www.blockseven.biz/

Great article guys. You are doing beautiful work. It is so cool watching thoughtful approaches and best practices in an emerging field develop from scratch.
Two advantages you didn't explicitly address: security due to potentially smaller attack surfaces and the general goodness of totally or more fully decentralized implementation.

So many developers these days fall in love with the decentralization ethos of Bitcoin and then what do they do? They go out and start a state-registered company and build a centralized software service that makes use somehow of the Bitcoin blockchain. Everybody trots out Mt. Gox as a cautionary example at this point in the discussion, so I may as well pile on.

Of course both of those approaches are perfectly reasonable and likely appropriate depending on the business niche, but the point is we need to look at all angles of a problem and work towards decentralizing them to find better solutions, if they can be made cost effective.

To be sure, developing an ÐApp requires careful attention to the cost of computation and storage on the blockchain and often some of these will more properly belong on some other resource. But centralized front ends and middleware present rich attack surfaces to dark hat “security consultants” who get paid as much at they can take as they point out flaws in the systems they have chosen to look over. Putting a front end in the EthBrowser and having the back end blockchain cryptographically integrated presents a very small attack surface compared to web sites hosted at centralized cloud services.

Notice to anyone actually trying to read through the implementation contract: this was coded in one of the languages that Ethereum supports: the Low-level LISP-like Language (LLL). Please note: low-level. Contracts can be coded at a much higher level of abstraction in Serpent, and simplified variant of Python.

Nice idea.
good luck with that!

I like this. While some people might not like the idea of incentives for donating, the fact is that most people are more likely to donate if they can get something out of it. I see it as more of a win-win than being greedy.

Thanks neil95—I very much agree. But this is also just my personal point of view. To tell more about this we need much more data and A/B test it. We will publish our experience and discoveries once we have enough data. Stay tuned.