I have only 4 females on a total of about 120 contacts on my list including single people with multiple IDs. On ICQ I have only 3 people one male and two females. On MSN I have about a dozen contacts, most of them university friends with a few people I met on Yahoo! with a total of four females only.
The ICQ lite I use is too invading, it's everything but discreet and it's not very convenient to use and it looks ugly,it's overloaded with commercials a little like MSN and it's not easy to hide and I have yet to find the time to customize the settings in the way I would want. But I chat once in a while with the first two young ladies I met on ICQ. I can't say the same about the first girls I met on Yahoo Chat, the only reason why I still remember their names is because they are girls.
It seems people are more likely to fill out their personal information on ICQ or maybe it's just that their search feature works quite well, you can search people by interest, location, etc...