Question, to create an "As Seen On Logo" such as the one on this website header www.shoulderpainnomore.com/, do I need to actually contact to these companies? Or if I do actually have a video on Youtube, etc, I can just make a similar logo and put it on my salespage?
Nope. If you do have a video on Youtube...you don't need to contact them at all. Go ahead and create your logo.
You have no legal right to use the logos in that manner without permission. You can say "as seen on ..." in words, if it is true, but not the logo. Of course, in most cases the owners of those logos would not really care unless you are doing it in a way that implies that they have endorsed your product. After all, it is more free publicity for them. However, there is a difference in getting away with it or having a right to do it.