Though I have not been a victim, I have been the target of several attempts at the scams...I am too jaded to fall into that love trap, scam or not. I hate being burned....too many times...finding that special someone has been a tough time....I meet someone that is a good match, they are already married....and I do not want to break up a marriage...the same could come back upon me...karma and all that.
But I do agree, it would be hard to administer and likely costly on bandwidth useage. Of course, simple contact arrangement itself is the primary focus, so it could be self limiting that way. Most people may look up a profile and contact the person anyway, for any reason. Most forums are built like that.
I don't use the online dating thing because I consider THOSE a scam. Many of the so called matches I am presented with are not attractive to me. For example, I consider a little extra weight to be perhaps 30-40 lbs over a typical weight vs height standard...for example, I am 5'7 and about 180-185, idealy I should be around 160-170...I am by far not fat and consider myself a "few extra pounds" as some dating sites define...some profiles I've matched to, the women are full on obese. Sorry for appearing shallow...but to me, the physical appearance of a potential significant other is an important part of the attraction...I do not mind a few extra pounds...but NOT 100 or more. I digress...
The dating sites expect me to pay to contact someone I find attractive or comes close to the qualities I am looking for...I may as well go to a bar, at least then when I spend money, its on a beer and I can enjoy THAT while perusing.
As for other points, most of the previous posts covered those concerns.