Maybe you could try to find somebody to take over or help you maintain it?

I've got friends who've helped, now and then. But all my friends are either too busy being successful in their career, or too fundamentally silly and unreliable. That said, I don't rule it out. It'd be a shame for the site to disappear off the web, forever.

Also, there's 701 cards. I have this mad idea I should get to at least 1000, before bowing out.

It's a good project. I had a look at a couple and they were very funny but I won't look at all of them anyway.

Just keep the site up sounds enough!