I haven't tried any gambling site except bitvest, but it's not easy to win, the chance of winning is getting low as you change the rows and make the wins bigger...But in my opinion, you won't earn big in gambling when you don't invest for your bankroll... and still it all depends upon your "luck"...
Obviously, gambling is not a way to multiply your bitcoins, even if you have a lot of bitcoins but still the chances the losing them is far more then chances of making them more, you may win 1btc/hour in gambling but there are more chances of losing 10btc/10mins, so it is probably not a good choice if you want to earn profit, if you want to play just for fun then go for it without thinking of anything with just a little amount, if you get lucky you will earn also from that small amount and if you are not then you will lose it.
Yeah your right honestly it can't help if you are looking for earnings gambling is for fun and not for earners you should and you must know first what will happen to your money if you just gamble it.. you may lose your money or you will win..
If you are just want to earn bitcoins better to choose a legit way.. why dont you try to join in signature campaign.. so that you can earn bitcoin while you are posting here..