Your point is valid in that the domination stuff is a niche. Even though most WG profiles list domination and a few fetish related things, only about 10% of the WGs actually know what they are doing, so very tricky to find the right WG.
There are fetish sites, but fluffy is at a whole new level on them, at least here the reviews are non-biased(mostly), so if i'm going to be reading this site' I'd prefer to contribute back as well, karma and all that
As for gifts, I'm of the view there rates are enough, years ago I once paid for some sessions in advance as a regular WG was struggling, she promptly retired and shacked up with another punter, lesson learned