300x250 to skin

Published by: Jerry Ostradicky , Zillow.com
Published on: November 30, 2012

Hey guys,
a while ago I saw a 300x250 user-initiated expandable ad, that when you closed out of it, it turned into a skin on the page. I can't remember where I saw it and all the vendors I've talked to have never done anything. Has anybody done this before? Any ideas for vendors?

Thanks
Jerry