[Editor's Note: YouTube is adding advertising to its mobile site.] Michael Learmonth - Advertising Age - 3/9/10 NEW YORK (AdAge.com) -- YouTube has spent the past year putting ads in every corner of the site, from big, splashy homepage ads to pre-roll, post-roll and overlays on video. But one aspect has remained curiously ad-free: its mobile site.

That's about to change. Mobile ads are YouTube's latest offering to Madison Avenue, and three advertisers are giving it a whirl: Mazda, Kia Motors and Sony Pictures for "District 9." YouTube tested mobile ads with L'oreal and Land Rover last summer. Read the full story.