I'm doing a format change for a website. I think (probably through AdManager) I'll try to sell some ad inventory on my own. The unsold inventory will show Adsense.
In regards to designing ad space to sell, the traditional Banner Ad and Leaderboard ad formats just don't fit in well with my site's design.
Historically I've used the Wide Skyscraper for ads. My pages' design could also adapt to either a Medium Rectangle (300X250) or the Large Rectangle (336X280) size ad block instead of the skyscraper.
In regards to making my ad space as attractive to advertisers as possible, which ad size besides the Banner Ad and Leaderboard sizes is most popular with advertisers? Or, maybe this isn't much of an issue?