I actually wrote a dating program once, in BASIC. It did a simple correlation between answers on a questionnaire. I gave the questionnaires to my friends to get some test data. To got sample questions from three real dating services, but I used fake names (two male, one female) on their sign-up form so I wouldn't get on their mailing lists under my real name. The whole thing was just for the programming fun, not a business I was trying to run, and nothing further came of the effort.
I still arrange dates online, however. Just the other day I iChatted my wife, who was upstairs while I was downstairs, and asked if she wanted to go out to lunch. She said OK, so that online personal encounter had a happy ending! Does that raise the online dating success rate to 66.7%?