clickbank vendor question

I glanced over the ToS. Youtube doesn't say anything about content that can be embeded to transfer any sort of right to those embeding it.

Youtube only covers their own kiester in that regard. By the standard "in using this service you grant a non-exclusive-royalty-free-sub liceable-yadda-yadda". Which protects them should any of your content be used in anything they do as part of their business.

In fact, the vast majority of content on Youtube is ironically against their ToS. It all depends whether or not the copyright holders wish the content to be removed.

Just because it's on Youtube doesn't mean you're free and clear to use it, especially if you're using it a commercial product.

Fair Use is not 100% protection from potential infringement. Especially in commercial ventures. It's largely for educational, critical, news reporting, etc.
Things where you're not making a direct profit from the work containing the material in question.

Even as examples in your product, you're still using someone else's work to illustrate your points.

You can't simply claim "Fair Use" it is a rather complicated matter. They look at the nature of your work, the nature of the material in question, how much of it you use, and how it affects any market value and right to profit of the owner of the material.

If you're using another's work in anything like this, You need to contact them seeking permission or license to use their work.

Did you know the music you hear in stores and restaurants has to be licensed for public use? Even if it's through a radio service, which also has to license the music. Most places pay blanket licensing fees to cover "public performances".

The only way to totally be free and clear with your products and productions and avoid infringement issues and bypass licensing is to produce ALL content yourself right down to any generic background music you may use.