Adultfriend and dating

, it brings together like-minded couples in a non-threatening virtual space, so they can get to know each other before committing to a physical date.

On top of the countless mainstream sites, there are specialized ones to help you find someone with the same religion, interests and sexual preferences -- whether you're seeking a friendly relationship, life partner or a one-night stand.

There are serious pitfalls to avoid, of course: dodgy sites, "catfishing" and, worst of all, online predators.

The concept of meeting in cyberspace predates the World Wide Web.

The oldest dating site that's still around is Matchmaker, which started as a dial-up BBS in 1985 and ran on a Radio Shack TRS-80 with modems (above).

At first, it was a crude listing of mostly computer nerds within the same area code, but it grew to include email exchanges and became one of the largest pre-web email networks.

Eventually that site and others joined the internet, and today, dating sites in the US draw nearly 30 million unique visitors per month.

Some of those, including let you browse potential mates for free (supported by ads), while offering a paid premium option with more features -- advanced searches, message read receipts and so on.

Another well-known, mobile-only site is , aimed mostly at people looking purely for sex.There's no reason why you can't play the field with dating sites, but they vary widely in reputation.The top 20 in terms of unique visitors (according to Alexa) are shown above.They're ranked not only by size and type (romantic, friendly and sexual) but also reputation, as determined by rate "poor" and "very poor" in reputation, respectively.Such sites have been accused of billing customers after they've canceled, inflating user figures with numerous fake profiles and rampant prostitution.Though rating individual sites is beyond our scope, we've compiled recent rankings from several sites like pointed out that the site has "far more search options than we found in any other dating site," including physical appearance, exercise frequency and occupation, to name a few.