Question about Affliate link in Youtube comments?

So I have an affiliate link to a clickbank product. Let's say it's for a gardening product. One way to create revenue would be to put it in the description of a Youtube video I made, and then hope people click it and make purchases from there. Instead of making videos, though, what's stopping me from going to, for example, a popular gardening youtuber and simply posting my affiliate link in the comments? Why make a channel when you can use the views from someone elses?

Also I have my affiliate link cloaked with the pretty link plugin on my wordpress site. It says how many hits I get, but not whether or not I made a sale. How to I determine if any of those hits generated a sale?

Sorry for the noob questions, I'm new to IM.

first answer , read http://www.blackhatworld.com/blackhat-seo/youtube/622390-youtube-new-comment-system-discussion.html

"How to I determine if any of those hits generated a sale?" => it will answered if you take a action