Excellent that spiral won, me and my girl friend spent last night wracking our brains trying to solve these. I've never found any gambling appealing until now, thanks for coming up with something fun and creative.
I'm very happy that you like it AngryCatfish.
One idea we had was what if the amounts rewarded started higher, and as the picture begins to clear the pot decreases (still going up with guesses of course), that way people are rewarded with earlier more difficult guesses.
There are many different ways the reward system could work and honestly they all seem fun to me. I choose this one because it guarantees that at some point, every picture will be worth betting on. The way it worst now the starting pot is 4 times the bet. So if by the time you are 25% sure that you know the answer, you HAVE to play. And if you miss, you increase the pot which probably means that someone that was 20% sure that he knew the answer, now HAS to play. In theory it can cause a chain reaction of bets, which I believe we witnessed on the "goldfinger" picture last week. I am a bit afraid that if the starting pot was decreasing, it MIGHT in some cases cause some of the harder pictures to be not worth betting on. If you start for example with 20% certainty about your answer and then, because of the improvement in the picture you get 5% certainty every hour but the starting pot decreases so it's always less than 1/certainty*bet then then nobody should be expected to bet on the picture. I would have to manually check pictures to evaluate whether they will be easy enough at some point to be worth the bet (which is impossible since my opinion would be highly subjective and biased).
Bets are still few in numbers so I don't make any profit from this, just very minor losses. My ideas to cope with this currently are:
1. Spend money on advertisement. The bad thing is that it looks like that most people that visit the site through ads don't place bets. The highest bet/visit ratio is the one from people coming over from the bitcoin wiki, this forum and through betwithcoins. Obviously this is because of better targeting. Maybe if I did a custom deal for advertising on some other site, or perhaps betwithbtc, I would get more players for the money spent.
2. Do an IPO and sell shares to earn money and have a few people (the shareholders or "chairmen" voted by shareholders) to advise me on how these money should be spent to advertise and develop the site. Shares will pay dividends from the equity.
3.Increase the starting bet AND also increase the fee. An idea would be startingpot=9*bet and fee=90% of bet. This would cause the chain reaction to happen earlier BUT it would also mean that multiple bets from a single player wouldn't make that much sense. Right now it's 4 times the bet and 40% fee so you can bet a second time to regain 60% of the previous bet plus the pot. 90% fee would mean you only recover 10% of your previous bet by betting again. In both cases (4x/40% or 9x/90%) the breaking point for me would be 10 bets per picture. That's when the site starts earning something.
4. Increase the starting pot and keep the fee at 40%. This would mean that my breaking point would move to more than 10 bets. Making the starting pot 8x the bet would mean I need 20 bets to break even. I doubt that this is viable for the time being. I believe it will be viable in the future but I don't know how far this future will be so I don't won't to play with the starting bet, increasing it today just to decrease it next week/month.
5. Make the starting pot 10x the bet and increase the fee for the first 10 bets to 100%. This means that in during the first 10 bets the reward will be huge so many different people will have an incentive to try one answer each (there is no way to win back your money spent during the first bets though so I don't expect a second answer for most players). After 10 bets have been accepted the fee is reduced to x% (x could easily be lower than 40% too at this point). This solution has a few problems. First of all it increases the complexity of the site, both for the development and the players. Secondly it will be somewhat hard to be certain whether you bet will fall into the first 10 or not, thankfully this uncertainty is one-directional: you expect it to have 100% fee and it ends up having less, which is not bad. If you expect it to have less than 100% it will never have more than what you expect. So my main objection here is the complexity but if people like this idea though I shall seriously consider it because it offers a middle ground between (3.) and (4.), it increases the starting pot, this rewarding early players more, while keeping my break even point the same (10 bets).
EDIT:
Two more pics: