getbig viewers are very shrewd and wise. Many of us know that *some* supplements are useful in some aspects, but that there are no miracle workers.
In other places, a video like that would boost sales, no doubt about it. Imagine seeing Tiger Woods training for an hour with some "sepcial swing" machine, all the while talking about how much it helps him. Imagine seeing Kobe telling you for 60 minutes that the new Nike Anklebiter has special cushion for the heel which allows you to play better D, all the while doing defensive drills.
It works. This is a highly effective product placement, you have to admit, even if you don't agree with the product claims.