I'm curious about what is considered an ad. I don't intend to run any ads on my site like Google AdSense or anything like that (my theme isn't even suited for placing any graphic art). On the other hand, I help others set up their logs and this question has come up more than once.
I've seen many blogs that have "ads" in their sidebars. Sometimes they're "sponsor" links, or links to companies the blogger likes. Sometimes it's for the business the blogger has (perhaps they're an architect and use WordPress as a stand-alone blog and have a graphic link to the architecture firm).
What, exactly, is an ad? I'd hate to set something up innocently and then be slapped with a violation…
Blog url: http://sanctifiedbrother.wordpress.com/