I have done it and been on quite a few of the sites. I met my current partner online (together 4.5 years), dated quite a few others and had a few disasters! There will be people who say there are "red flags" about certain behaviours but I think this all depends on individual circumstances. 
My partner, who has Asperger's syndrome, would bring up quite a few of the common red flags.
When I moved to the USA in 2008 it was the only way I had of meeting people as I didn't know anyone out there when I moved (I had a phone interview and hadn't met my work colleagues). I got onto the chat rooms of some of the dating sites and just talked to people, after a couple of weeks started to get to know the regulars and arranged to meet up with them at a venue they attended each week. It was a much much better way of meeting people than going as a lone female into a random bar in L.A. I met some of my very good friends on the same sites and several partners.
My advice would be
1. Exchange e-mails, texts, chat on the phone, Skype, however you want to do it but communicate several times in advance.
2. Set up a neutral meeting place in public
3. Either have a friend go with you or, and this is what I usually do, set up a safe call at a pre-determined time with a friend who knows where you are and who you are meeting.
4. The vast majority of people are perfectly normal and seeking the same thing you are. If you feel that the person isn't who they claim they are or you feel uncomfortable thank them and leave. Do trust your instincts. I have ignored them in the past to my detriment.
5. Have fun!
Hope this helps.
My partner, who has Asperger's syndrome, would bring up quite a few of the common red flags. When I moved to the USA in 2008 it was the only way I had of meeting people as I didn't know anyone out there when I moved (I had a phone interview and hadn't met my work colleagues). I got onto the chat rooms of some of the dating sites and just talked to people, after a couple of weeks started to get to know the regulars and arranged to meet up with them at a venue they attended each week. It was a much much better way of meeting people than going as a lone female into a random bar in L.A. I met some of my very good friends on the same sites and several partners.
My advice would be
1. Exchange e-mails, texts, chat on the phone, Skype, however you want to do it but communicate several times in advance.
2. Set up a neutral meeting place in public
3. Either have a friend go with you or, and this is what I usually do, set up a safe call at a pre-determined time with a friend who knows where you are and who you are meeting.
4. The vast majority of people are perfectly normal and seeking the same thing you are. If you feel that the person isn't who they claim they are or you feel uncomfortable thank them and leave. Do trust your instincts. I have ignored them in the past to my detriment.
5. Have fun!
Hope this helps.
. The best relationship I ever had. We're getting married soon 
I know, but happened to play in the same guild, and when my x and I broke up he was very supportive (in a friendly way). after a few months one thing let to another and we decided to meet up.. which seems harmless if it wasnt because I lived in Denmark and he in England 
Not exactly love a first sight, had our problems due to distance, but made it work, I moved to England after a year for us to try "a normal" life together, were not married, buying our first house and hopefully gonna start a family in a year or two.
