It all depends on how often a person plays. If they only play occasionally, regular promos are enough. But if you play regularly, a loyalty program can be quite useful. I pay attention to it in these cases. For example, I liked how it's implemented on Ludios. The site offers both a ludios bonus for new players and additional offers for active players. Conveniently, everything is gathered in one place; you can simply log in, see what's available, and decide if it's right for you. Nothing intrusive, just a selection of options from which you can choose.