The differences however, are considerable, when looking at BDSM relationships and merely adult, casual ones: ALT offers a huge number of questions to determine your specific kink, and each one is easily searched by its paying members.
For those not willing to pay the (somewhat steep) fees, try hanging out in the groups or chat rooms to see if someone nearby shares your interests.
Sadly however, there aren't a lot of BDSM dating websites available today, mostly because it's a smaller market for dating singles and a few well-known brands own most of the traffic.
Note: all of these dating sites are meant for adults only, and many display adult-oriented images.
I may get blasted by Fet Life's owner, John Baku, for listing Fet Life as a "top" BDSM dating site.
Think of it as a Facebook for kinky folks, and you've got a pretty good idea as to how the underground yet well-populated site works.