Luckily most metrics when dating are pretty obvious, for example, height.
|The only number that matters.|
When using Tinder, I at first figured that girls were lying about their height because they all seemed to be 5'11. Almost all of them that listed their height seemed taller than me, and I'm not especially short (at 5'8). But my new theory is that the girls on Tinder are in fact on average TALLER than normal girls. I have my age group set to look at girls I would actually date - i.e. 38 and slightly younger. Is it harder to get and keep a husband if you are a tall girl?
There are probably other numbers, less obvious, that are skewed in the online dating crowd. If guys are selecting for girls "my IQ or less" then the girls left on Tinder are going to be smarter than average. And of course, the guys will be shorter and poorer.
I dunno - there's a lot of good data science to be done in that database. But it's interesting to try to think about hyper-rationally, because usually we are attracted to people and don't know why. Our brains have a natural camouflage that protects us from over analyzing these things the way a smoker finds a thousand rationalizations for why they deserve a cigarette without ever realizing they're rationalizing it.