[kivihiinlane]

This wouldn't work for me.

My browsing habits are bit different, I'll browse indexing sites (HN, reddit, etc.), click on interesting title, quickly scroll through site, read introduction and if it seems interesting, I'll leave the tab open and go back to indexing site. Now what would happen is popup would show, my rage level goes through ceiling and I quickly close the tab, no matter how interesting the topic or product was.

Wouldn't onclose work better for examples like this?