I have a profile on OKCupid, and about six months ago or so I actually spent the money to be able to see who likes me. Apparently, the women who like me most often are Pro Dommes seeking dedicated submissives who are willing to "donate" or "make a tribute" in their honor. Obviously, I find this deeply disappointing, and in all likelihood I doubt I'll continue using this service once the time covered by this payment has expired. I can't say I feel cheated, exactly, since there was never a guarantee that anyone would like my profile at all. (Fun fact: the data for one site, called Tantan, seems to show that men like 60% of all female profiles while women like 6% of male; the least attractive women receive attention equivalent to the most attractive men.) Nevertheless, the quality control is simply abysmal, and I really expected that the people running the site would manage a more...professional operation.
One other observation, and this, I think, has bothered me even more than the proliferation of scam profiles: I've noticed that a lot of women have started to emulate the worst qualities of men in terms of not making the effort to fill out a profile. Quite frequently I'll notice someone with a high match percentage and then find that we have that high match percentage because they haven't answered or questions or written anything substantial, so the site's sorting algorithm just does the best it can with the information at hand. It's extremely frustrating to bring up a profile only to find that the person has written nothing more substantial than, "Message me to learn more about me!" That defeats the whole point of a dating site! It's efficiency lies in the fact that you already know quite a bit about a person before you meet them and you decide to meet them specifically because of what you know about them!
Modern dating. Hell of a thing.