Other than the dangers of heffalumps as mentioned by BigSaint above, it seems to be time-intensive. Probably takes a lot of typing just to shag some.
I go through the ads sometimes. The reasonably good-looking ones (with less facial hair than your dog's butt) all seem to have a long list of requirements, like: income not under $100,000/ yr. , must have all his teeth, be capable of intelligent conversation (does a discussion of turbo map efficiency count?) and "must be able to keep up with me" (while she plays tennis, talks to her accountant on the cell phone, plays 18 rounds of golf, jogs 6 miles, then showers & has two lettuce leafs for lunch) and not only that, half seem to be flaming liberals. The politically conservative ones all seem to be heavy smokers, which I ain't.
Some years ago, my total haul (the ones that wrote back, not the ones I followed up on !!!)after one year added up something like this: five heffalumps( skinny online picture taken during their teenage years) one manic-depressive , one obsessive-compulsive, four nymphomaniacs(Yup, I confess, I met two of THOSE

) one flight attendant(I think she had one guy in every major city) and three seemingly normal types.
It seems safer and less time-consuming to shag the factory or office skank.

Not that I do. I'm just trying to be funny, here.