A great feature is that you can like other people's personals and view who likes you, making it easier and less intimidating to reach out.
If you're aiming to find casual hookups, Adult Friend Finder boasts a membership of over 14 million.
Soul Mate Find is geared toward people who are trying to find life partners.
While membership on the site is free, users are encouraged to earn "credits" by logging in everyday or by referring friends to the site.
There are no special algorithms, no complicated technology, just simple chat rooms.