Thanks so much, especially for your ideas. I wanted to avoid any sort of sign up, so I don't actually collect the "crusher"'s name (just the "crushee"). The system will tolerate names within an edit-distance of 2, so many common spelling errors will be ignored (not to mention the added layer of plausible deniability). I also recently added a "really close"/"close"/"sorta close"/"way off" hinting system -- so when you guess, you'll see that the prompt reflects how similar your guess is to the actual crushee.
One thing I'm going to add is a little cookie-based cache of your recent cupidco.de tracking pages, as they start to get difficult to juggle after some time.