Bitcoinflips is a Provably Fair coin flip game that allows gamblers to win 200% on their bets.
If you say "win 200%", I expect to get my bet back, plus 200% profit. This is not the case, it's a simple double or nothing game (I win exactly what I have wagered, hence 100%).
You should adjust your advertising there to avoid misunderstandings, because I can guarantee those will happen.