Weekly promotion or bonuses is what I like and what's on my mind is something like a rake back or free bet depending on how much you wager on that week and of course you should have a wagering requirement as many users would probably take advantage of that kind of bonus considering that it is a weekly bonus.
Yeah rake back is more better than a deposit bonus since the rules on rack back are a little flexible compared to the on bonuses, so at that many prefer a no bonus on deposit so that their can withdrawal their winnings without any condition to wager a certain amount.
I personally do not like deposit bonuses and because of that I will not get attracted to any form of bonus no matter what they're promised what i normally do is to skip bonuses and play with my money along the way this is the best.
I do participate from time to time in deposit bonuses as it can be interesting depending on the wagering requirement. Sometimes it is 30x and while that is still extremely hard to do, it is possible to do. Best bonuses for me are like weekly or monthly bonuses without any wagering requirement.