Hey! I'm one of the cofounders of Cent. That link goes to the beta app which lets you earn Ether (the currency powering Ethereum) by responding to questions. You can also ask a question, provided you put a bounty on it.
Happy for any questions or feedback - we just launched Tuesday!
Recommend you identify in some way other than showing the age of the question which ones are past the answer bounty stage. Also, I think the questioner should set the lifespan, and it should be related to the amount of bounty offered - i.e. higher bounty allows a longer lifespan, (hopefully) soliciting a better reasoned response.
Yeah, looking at the stackoverflow model would be good.
It's also worth noting that the anonymous nature of this will probably drive down engagement. Look at Quora, people use it solely to build their personal brand.
Right now people would answer on cent solely for the money.
Let them do both so you can appeal to a broader market.
Happy for any questions or feedback - we just launched Tuesday!