The strange thing is the URL is the onclick handler on an anchor link. If you're doing to track outbound analytics, Google has information on how to do this in a better way http://www.google.com/support/analytics/bin/answer.py?hl=en&...

PS. I do like the site.

This is my question as well. I do wish I could ctrl-click or mousewheel-click to open up a new tab with the link. Also an indication that "e-book" is an amazon link to the kindle version. I (naively, of course) thought there were free e-book links there! Like for SICP or the like. (Totally fine there's not, I readily acknowledge it was a naive hope :)

To mask the affiliate links perhaps.

That was my thought. And if it's correct, it's not worth it given the aff link is visible at the Amazon page, and if there was ever a crowd that would know to check for it, this is it.

Anyway, there's nothing wrong with the aff links. Profit is fun.