As the name suggests, this type of bonus allows you to place free bets equal to the value of bonus. For instance, if you got bonus worth $100 at the time of sign up, you can place bets worth this amount in various games. This is really good option for trying new games on various casinos. You might get lucky and make some money without the need to invest anything.
Did any of you made huge money with this bonus amount ?
Yes I have a good experienced with that free bonus, never will forget that because that's my early days in crypto gambling. Back then, gambling sites competition is really tough so it's a must that in order to attract new gamblers, owners needs to do something and one idea is to give free bonus/bets. But is that really can attract gamblers? Yes it's proven but it will be more effective if the waiger requirements isn't that hard to reached.
Since it's free bets, then why not go all in and ignored risks? It's free after all If lose then lose, if win then much better. And that's it, after playing an automated slots, I hit a good multiplier, reached the requirements then withdraw. It's different for first deposit bonus and again I hit big multiplier and the rest is history.
But today this kind of bonus can't now be seen anywhere because of
a) tough competition
b) owners doesn't want to risks money
c) gamblers tend to stay at their usual gambling site.
I always stay away from them, the rollover requirements are usually way to big.
They use them to lure you in, get you playing, preferably addicted and in 99% of the cases they do not lose any money from it.
Take note that in the first place, that's obviously the purpose.