[3pt14159]

I've had best responses with Amazon's affiliate program. Made about $130 bucks from something like 5 or 6 blog posts. Hourly rate worth it? Nope. Was it fun? Yep. Basically what I've learned is that Google's dynamic ad placement is the last thing you should try. Putting in an ad (or affiliate link, there are even services that will auto do this with Javascript, so you're users wont see and you don't have to be part of a billion referral programs. Gray hat? Maybe.) that actually targets what you are talking about is so much more effective.

[nl]

I've written a context sensitive affiliate adserver that serves relevant ads via Javascript. That works reasonably well, but I do need to optimize the ads themselves some.

[3pt14159]

That is really cool. Have you open sourced it? It's JavaScript in the first place so I know anyone can see it in your site, but it would be cool to track it on Github.

[nl]

No, it's not open source.

Not much in in Javascript - just the part that displays the ad. All the intelligence is on the server, mostly in Java.