This is the first in a ongoing series of posts that I'll simply call "Quick Notes".
If I wanted to put ads on my Wordpress site, in addition to always-in-place banners, then I'd consider inline ads inside the post area. I don't want to chase my regular/dedicated readers with ad-filled content, so I'd be selective with how I publish these ads.
Google AdSense makes for a good contextual ad, it's just a text in a slightly different style. It's not as intrusive as image-based ads in the middle of a document.
For Wordpress sites, I'd use this plugin:
http://wordpress.org/extend/plugins/smart-ads/
On a site that is timely with content (meaning older content is not as important as the newest posts), then I'd opt to enable ads on the posts older than a few days or few weeks. Anybody looking at old archived content gets the ads.
I'm not a fan of ads. But they are often essential, and this is merely one more technique by which to make it happen in a reasonable manner.