What I loved about OD was that it was like a big shop window where you could browse to your heart's content. You would never get such a variety of available men/women in your local pub!
It also meant that you too were also in the 'shop window' 24 hours a day, rather than just on the odd occasion that you dress up and go out in RL. Must surely increase your chances of finding someone.
I think OP asked upthread whether people looked for guys locally or further afield. I did both, really. I was only interested in meeting someone locally (I think I set my criteria for about 30 miles or something, but I live in a rural area, so that did kind of limit things). I didn't really want the challenge of a long distance romance. However, I then did start chatting to a lovely guy who lived 100s of miles away - we both acknowledged that we'd probably never meet, but enjoyed emailing each other on the trials and tribulations of OD, and wished each other well when we each found someone.
The biggest thing for me (apart from meeting my lovely DP eventually, of course!), was that I would often find it really depressing to go out with all of my married friends, all dressed up hoping to meet someone, and never did. But then I'd get home, open my inbox and find a nice email from someone / or trawl Match for someone to have a chat with. It was a really nice boost that really helped me to stay positive.
Someone also mentioned upthread that they didn't want a picture of themselves on a public forum. I really struggled with that, but then I realized that anyone who saw me on there was also on there themselves and so in the same boat (or snooping, but hey ho). I saw quite a few people I knew on there (including my Ex boyfriend...aaargh!) which was a bit awkward. But I would tell myself that if it meant I would meet someone lovely, then who cares!