No I don't think it is just for weirdos. It's just a new and modern way of meeting people. Not all people have the opportunity to meet people of the opposite sex in their daily lives and not all people frequent bars and clubs and the sort of places a lot of young people hang out.
You have to be careful obviously, but you have to be careful about any new people you might meet.
I think they are great for people who are adult enough to know the pros and cons and not suitable for very young people.
Can I recommend any - well 'no', I have been married to the same man for near on 40 years!!