The question is perhaps not whether or not there is a market for it, but whether or not you should promote it. What value can you add to pre-sell the product? Are you knowledgeable about Adwords? Anyway, a lot of people have difficulty with Adwords and there are plenty of complaints around the web from people saying they lost money. Not to mention the creator of the Clickbank product obviously believes there is a market for his product (otherwise he/she would not have bothered to create the product)
Are you looking for those customers who need adwords help ? well there don't exists any market as i believe. Just a help, see adwords section in this forum.