No significant experiences good or bad to contribute. My guess is that there would be more trust in paying a well known search engine to run an ad as opposed to an individual website.
My gf offers ad space for sale (
Handcrafted Beaded Jewelry by Jades Creations - Unique Designs in Handcrafted Beaded Jewelry) on her site. IMO it doesn't hurt to offer the space. I'd guess that the folks that would do best in offering ad space are those that run forums. Possibly you could incorporate a forum into your site.