I just made a visit to parody newsmagazine The Onion and was presented with an animated ad that I sat through before being redirected to the main page. But it was worth it, because the folks at The Onion were good enough to label this delay a premercial. The LangMaker site has a definition:
Part of Speech n.
Etymology [< pre- + commercial.]
Definition A web advertisement that appears before the site's real home page is displayed. Example: "I hate that The Onion now has a premercial, but I've been reading the site for free for years; I guess even humorists have to pay the rent."
Submitted By Jeffrey Henning
Date Submitted Friday, July 30, 2004