Director Jason Woliner ("Eagleheart," Borat Subsequent Moviefilm) revealed on the podcast Podcast the Ride that in 2010 he directed a fake commercial for "Billy Glimmer," a Ben Stiller character who is a Las Vegas impersonator.
It was a demo for a possible movie (or web series) about the character, but the project never advanced. At the time, Woliner created a YouTube account, "Top Las Vegas Entertainment & Shows," and put the fake promo video for the Billy Glimmer show among other real but similarly cheesy Las Vegas trailers.
"Have I told you lately I'm Rod Stewart?"
As of the podcast airing, Woliner said that nobody had noticed the Ben Stiller video; it sat there for six years, perfectly camouflaged with other Las Vegas shlock. It had about 100 views, and Woliner believes those were all from himself, uploading the video to check if anyone found it.
It's actually very funny, with Stiller satirizing a glitzy, shallow Las Vegas entertainer, and the audience roaring with laughter and applause at even the slightest and hackiest evocation of a celebrity. Glimmer is all audience-pandering and zero talent.
Woliner said the character is loosely based on the late Danny Gans, who was a hugely successful Vegas impressionist. And I found this promo video for Gans that looks like the inspiration for the Glimmer video.