you should not to understand. your site depends on new deposits to pay the old deposits, it makes her very dangerous site for anyone investing, then we have the question of confidence, the history of  bitcoin double sites show disappointing results, 99% of all double bitcoin sites are scam, how do you expect someone to believe in your site? if people learn from past mistakes they will not invest in your ponzi site because they know that: your site is unsustainable, illegal and is not reliable