Assuming OKC's target market is the relative majority in English-speaking countries it really doesn't take much crazy math to find matches, as in the matching facility is not going to be as important as the random number generator (or trained monkey) that is filling in the matches. All that really needs to be taken into account are features of the prospective match that the two individuals WANT to be taken into account(age/height/race/income level/political/religious). It isn't that complicated, especially since one of OKC's tactics is to use quizzes/'looking for friends' to break the stigma of online dating.

What is the stigma of online dating?

Obviously the implied answer is that if you are using online dating then you cannot find a date IRL. Or perhaps a kinder answer would be that you have too much going on to find a date IRL. This is the same principle as a meat-market nightclub/singles bar where the bouncer lets the guy with the two attractive women in, but the pack of forever-alones get locked out. Then the slightly wealthier gentleman pays $ to the nightclub to get in, for the opportunity to pay $ to one of the attractive women (in the form of a drink) for the chance to talk to her and (hopefully) get sex/affection/phone #.

Of course this is all crazy, but it is a way in which many bars/nightclubs/online dating works. If OKC can attract attractive women with quizzes/validation/'looking for friends' and associated kitsch, they have it made.