It was just a couple of months ago that 37signals launched their 37signals Job Board as a minor sidenote to their blog. The offer was simple. They'd post jobs for 30 days at a time for $250 per job. They have a highly technical audience, so if you want to target those people with your job ad, you'd do well to advertise your job there.

I just took a look at the current jobs and counted 70 jobs during the last 30 days. That's a possible $17,500 in ad sales. They may have cut a few deals or offered some price cuts for a few people, but I'd bet they still took $10k for doing, well, not very much. The app powering it could have been written in a day. The value comes from the 30,000 regular readers of their blog. They've taken an audience and turned it into, possibly, a $200,000 annual revenue stream with a day's work.

AdSense may not be the big money spinner for your blog / site. If you have the right audience, there could be hundreds of thousands of dollars of untapped potential somewhere around the corner..

Perhaps it's time Code Snippets ran job ads instead of PPC ads? $100 per ad for 30 days, you get to choose whatever tags you want it to appear for at the top of each page (so if you were targeting Ruby programmers, you could promote on the 'ruby' and 'rails' tags, for example).. and so on. Thoughts?