hi there
i didn't answer earlier cause i had a really busy week and made a lot of learnings as you might imagine. always afraid of the tiny vserver not being able to handle the peak traffic... the database crashed once (we've been able to recover it) a smart guy (hey stranger, you deserved it) took our first days earnings due to a exploit (we fixed it) and we got lots of feedback (thank you all).
we might be new in gambling but we are not in onlinebusiness and we take this business serious - in particular as our first week was a quite successful beta phase. new design is in progress and new servers are ordered as well as SSL certs are.
the claimed 25% rake is not true. it would be true if everyone would always have to play all rows but you can stop the game after each row and take your winnings so far.
the 3x8 for example (which is btw. 3x6 now cause it's a bit frustrating to pay out a 20x bet when you have not accumulated much funds yet. a lucky guy deposited 0.3BTC and cashed out about 13BTC yesterday so he earned more at this site than we did to date )...:
let's say you have started with a bet of 1BTC and have just passed the 5th row which means you have already won 6.4BTC and are now betting these 6.4BTC to possibly win an amount of 9.29BTC so the actual multiplier is 9.29/6.4=1.45 like in the first and every other row.
the chance to win the 6th row is also the same as the chance to win the first or any other row, namely 66.67% not 8.78% as you claim - 8.78% is the chance to win 6 rows in a row.
so as Wassupia already said the rake is ~3% in every case and i'm waiting for apologizes