First of all, it's Bustabit and not Bustsabit. It is said in their own website that the key to beat their house is to take advantage of their winning bonus. There are people betting at 1.00x (the lowest multiplier possible) so if it instabusts at 1.00x or any low multiplier, they will get a bigger amount of bonus. Of course the higher the bet amount, the higher the bonus amount you'll receive.

The only downside to this is that it's quite hard to recover if it instabusts at 0.00x and there are times when it happens twice with just a couple of rounds of difference. I don't recommend this method but Bustabit says that is the only way to beat them so it is your choice. After all, it would still depend on your luck if you're going to have a 0.00x bust.