If you are unfamiliar with clickbank, then you will need to watch that video to see what the site is ask about.
It doesn't matter if you have some experience with it or not, the question still applies, what are you using clickbank for? This critical because you need to understand which products are a good fit for your blog. This is considering if you have a niche oriented blog.
For example, let's say you have a blog about editing Photoshop images. You can go to clickbank and find a product that is talking about Photoshop editing.
You wouldn't use a generic photography site because your whole blog is revolved around the image editing niche.
So as you look through clickbank to find a digital product to promote, you have to ask yourself, what exactly am I looking for? And is this product a good fit for my blog?
This is what your mentality should be generally in order to effectively find good products to promote.