I did a feature on online dating when I worked as a hack, and the general consensus of those I spoke to was that the whole thing was a dangerous lottery. Women tended to get targetted by married men in search of a bit on the side, while men tended to attract the desperate, possessive types.
No-one I spoke to was really happy with online dating, and few would recommend it, although many of them saw it as a way to while away dull times in the office by inventing strange personas. One guy admitted to being several women just to take the piss out of other blokes!
Personally, I'm happy with this place - more love and affection here than a squillion chat rooms, and who needs cyber-sex when you've got 'Spaw's vitual farts :^)