Just tried it out.
~3 hours +73 satoshi.
Used it on a working laptop (i5 4x2.3Ghz). Settings were: 2 threads and 50% and 4 threads 100% (1.5h per each).
While was on 50% I had on youtube, Hearthstone game and Bitstamp trading view window, not considering 3 xls working windows, outlook and ie with some working pages.
Imo, this "mining" can be easily used in background if:
1. you are freebitcoin faucet user
2. you are not overloading your pc/lap with it
Free satoshi for just keeping one browser window on (even on minimum "mining" settings) are still free satoshi. So why not?
If you look at your 73 satoshi reward for around 3 hours worth of mining, then it can be seen as a pure waste of time and resources. If anyone is that desperate to make a few dust particles, then just farm your way through any faucet you can find -- there are several apps that you can install that will allow you to earn like 1000 satoshi per hour in total. It's still peanuts and not worth the time you put into it, but at least its far more 'profitable' than what you are doing with your browser. It's just a lame way for people to earn something while they feel it is completely effortlessly....
Actually considering that values has not live updating - I saw 214 satoshi after 5 minutes of turning this option on again. So not 73, but it does not really matter.
Regular faucets has tons of ads and annoying captchas. This mining page does not. Turn it on, for lets say 10-25% of you installed power, and go do what you want/need.
I dont want to go deep into discussion for coin hive mining and other pc mining issues - this is completely same shit, fee % slightly differs, but values are low so in short or mid term run it doesnt matter at all.
Same for spending resources. Cmon guys, what resources are you talking about? This is not a farm, this is regular PC that with or without mining works 24/7 or close to it. This is not a problem nowadays to upgrade PC once per year or two. Adding some shitty mining service into background process is waste of resources? You might be joking.
If someone will spend 100% of the only PCs power 24/7 for this shit (considering that it wont be possible to run another processes because of lags) - only in this case this is waste of resources. But I think that no one can be such a fool.
Main point that I wanted to stress, that this browser "mining" provides you with
free satoshi/monero for doing nothing, not even spending resources. This is why I pointed some preconditions for it to be useful, that together with your PC turned on 24/7 (with idle and lock, do you maybe know someone who completely turns off PC for a long term in regular life?) gives you
free coins.
Yes, value of this coins today is not worth it, but 50k satoshi (or its worth) earned today can turn into 10k usd in 5 years. Who knows.