During development of our Whirlwind Index product, we developed and deployed some live social matching solutions to enable us to better understand the way that people use sites.

An example of how a matching can be used on a dating website can be seen at Genuinely Looking.

If you take a visit to the above link, you'll find that the search results are based on a blend of the search criteria, and clicking on a profile will show how well each of the search criteria has matched.

The following example is how a member of a dating site will be matched up against other members:

Whirlwind Match Limited
87 Lovell Road
Cambridge, CB4 2QW
UK