Free bonuses from casinos are very good and attractive to all gamblers most especially when it comes without any form of strings attached to it, like wager requirements and game or wager limitations, some bonuses also come with minimum odd requirement which can limit one's ability to make anything good out of the bonus without losing it..
It's pretty much impossible to find such bonuses. Most of them have strings attached that limit you to what you can play, how much you can wager, how much you can win and cash out from the bonus and how many times you must roll the money over. Even bonuses advertised as having no wagering requirements is only partially true. Sure, what you win is yours to keep but you have to make that one bet to win something and keep your winnings. It's not money you can withdraw without playing. You are always giving the casino a chance to win it back.