I dated alot from online...never paid for a pure dating service though, although I paid to join a young adults group which was cheap for a year.
match.com seems more geared to people really looking to date while Yahoo seems to be geared for pick your partner for the night.
it goes both ways on either though.
If you see an 'airbrushed' head/body shot you can be sure it's a troll if it lists anything about how they can't ever meet a guy and they don't feel good about the way they look. Basically any pretty chick that says things like 'she can't find a guy', 'her last boyfriend told her she was ugly', 'she can find anyone that likes sex', anyone that lists 'I will tell you later' about their profession and lists $50k or 100k as the salary
I bit at a couple of these 'too good to be true' to see where it would go. One was an admitted 'escort' 1st date was $500, cash first....another one wanted me to show her how serious I was by shipping her two bottles of alcohol (1 wine and 1 jagermiester or goldshalger (sp))...wrapped in brown paper and boxed and to make sure it doesn't look or sound like bottles since 'her roomie' was an alcoholic and would steal them.
Now once she received the drinks she'd call me and give me her address to share them (problem was if I shipped something to her, wouldn't I have her address?) and we'd meet up the next night her roomie was at one of her many boyfriends houses...and we'd have a night I would never forget....+ she was a virgin and wanted her first time with someone special like me
Anyways we went back and forth, I told her I shipped it to something like apartment #104 when her's #401...told her I suffer dyslexia, but I'd ship her more (she emailed me in between and said 104 didn't get anything with her name on it so I said, I have a little alzheimer's too so maybe it was some other number I sent it to)....
Then I sent her an email asking why she refused my package, I even bought her the good stuff, but she sent it back

...she told me her roomie must have been jealous of what a great guy I was (she was bragging about me), but promised this time she'd get it, she'd be home for the next two weeks on her company vacation (spring break I think it was) so send it back fast and she'd make up the shipping costs to me

....
it went on a couple more times with emails back and forth, until she got pissed and told me to get help for my memory...so I finally asked if she was in middle or high school and if a guy or girl (hard to tell since they asked for wine, but may have been trying to score something for a g/f). I closed it with telling them I spoke to the police and they were coming to arrest them for solicting illegally shipped items in return for sex, they just needed one more email from them due to state statutes

They took down the ad that day and the email addy started bouncing about a week later...
I wonder how many guys though sent wine and stuff to them.
Another one wasn't so complicated, she/he wanted cigarettes mailed to her/him...in their profile it said non-smoker and very into exercise...they swore and stuff at me and wouldn't play anymore.
I have met a couple hot chicks from aol, but yahoo was scary freaking women, one I thought I'd give a chance too, ended up giving me a second picture that was a totally different person, but both had the same fake datestamp on it and her
name@yahoo.com on the pic. I have no idea what that ones motives were I ruined finding out when I sent both back and asked about them.
There was another one too good to be true also, but that was a real ad and legitmate, problem was with 'her' was she was a pre op transexual...just a face shot and upper body looked nice, not a beauty queen, the picture was airbrushed/glamour shot type and the ad talked how she couldn't met the right guy/they wanted to rush into sex and she was old fashioned, blah blah blah...I kept messing with them not knowing about the planned sex change (thinking it was another scam personal and was trying to see what this person wanted out of it) but they kept being polite and finally we started talking as friends every once in a while, she was interested in my dates mostly...then one day she/he told me why and how they wanted to become a woman. The person was cool about it, and not pushy or whatever, I felt bad messing with them at first and told them why I did it and about the other ads I ran into.