Add some noise to the image to make impossible comparing hashes.

Для лучшей защиты от ботов размер приза будет отображатся в виде картинки.
Ограничения по количеству обновлений главной страницы полностью сняты!

To better protect against bots quote (prize size) will be displayed as image.
Refresh limits cancelled at all!

Bot watches flower and make request if bounty available, entering your email. You receive letter and redeem Bitcoin.

Chinese kids decaptches it for few cents per thousand.

Totally agree. In Eastern Europe common business practice is to drastically increase price, than advertise big discount, e.g. 90%. It is very disgusting.

Jackpot is a big prize which will be paid when we could raise enough funds from advertisers.

We use CAPTCHA to protect current quote (size of prize) from auto-tracking bots. When our system notices unusual behavior, for some time user must enter security code to request the quote.

Good luck with your business!

My competing service Dailybitcoins.org works exactly as you suggested.

P.S. When your lottery would become popular, you must implement serious anti-bot measures. Currently my free lottery has about 700 unique visitors per day and I spend a lot of time to defend my site from cheaters and block bots. Today I have experienced massive attack from China, CAPTCHA probably had solved manually by poor kids and about 300 fake bounty requests was made. If I would't manually review all payments, my site would go out of business. So think more seriously about security. If you will not do this, your flower will wither very soon!

Именно так.

Go to the Stats section and you will see that there are always non-booby prizes available. Number of visitors have increased, so catching big bounty became more difficult.

Что конкретно вы имеете ввиду?

My competing project has this protection, also CAPTCHA, IP blacklist and even statistical analyzer. Regardless this bots still trying to cheat me. I give away big number of relative small prizes, so <10% cheat level is tolerable, but you pay only one big bounty per day, which gives big incentive to the bot makers and they can easily destroy your business even with few successful cheat attempts.

Another problem is that you give away only one prize per day and all people except one lucky will get nothing, although they have spent much time on your website catching bounty. This fact can disappoint and many of them could lose hope to win and never return again. I would suggest to pay some "booby prize".

I don't see any ads on your site. How do you monetize this service?

Бонус для рефералов увеличен до 15% от стоимости рекламы.

Я вручную отправлял эти письма. Если рассылать всем рекламодателям автоматически письма с одинаковым текстом они скорее всего начнут попадать в папку "спам". GMail не особо любит такие рассылки.

Referral bonus increased. From now you can receive 15% from each advertisement's price.

Jack of Diamonds, I don't know how this fraud classified in U.S., but in most EU countries typical sentence for this crime is suspended prison term for few years and if perpetrator admits guilt he can only get monetary penalty.

When you make order your IP, payment address and some other params are being registered along with time mark. When you try to get bounty again we check difference between current time and this time mark, if it is less than 24 hours, your request get rejected.