its all about economics…………….. (its not, but its a good starting point for an explination)
If everyone rated themselves out of 10 then that would be your buying power, and assuming an equal number of 10/10 men and 10/10 women etc youd get an equaly good match in a perfect world.
Now say 3.3/10 is rated on appearance, 3.3/10 is on personality and 3.3/10 is on other things like a fancy job, house etc. Obviously your personal oppinions dictate the exact weightings. So for example a dumb blond rates 3.3/10 and a rich, ugly, socialy inept, business man similarly rates 3.3/10.
Now you can only be rated on the first one by first impressions, but…………
if your seen chatting to a pretty lady (say an 8.5 on the above rating system) then other women will get an indication of what your other characteristics are like, based on the principle that a if she’s a good catch then so must you be (so your score jumps form a max of 3.3/10 to 8.5/10. Where’as an equaly good (or better) looking bloke on his own in the bar doesnt score as highly.
Try it, go for a drink with a friend/ex (preferably good looking) after work, then hang arround afterwards and see if you can get chatting to any of the other women in the bar/cafe/wherever.