The 5%
Ashley Madison's closest kept secret seems to have been the male (95%)/female(5%) ratio of their subscriber base. Either those 5% are awfully busy (!!!), or there are a lot of unsatisfied men paying money in the hopes that one of those 5% will pick them. Now, how many of the 5% are "women of negotiable affection" has yet to be determined...
Some sociology postgrad is going to mine this database for all it's worth and get a PhD out of all this.