When you work on a Facebook app, you need to customize the urls of your scripts and stylesheets to bypass their aggressive caching.

In my first, the markup was littered with urls looking like

    http://www.domain.com/path/to/stylesheet.css?v=20

After a couple of projects I noticed that the number was decreasing. As I was learning to work with their fucked-up FBML/FBJS/weird-corner-cases my code went through less and less iterations and the final numbers were lower and lower.

And I was a little happier inside.

That's gamification, but unintended.

Making it part of the product? I'm not sure.