Originally Posted by Baldbastard

This is an adult board so most of the tutorials are for that area, however there is no real difference with doing non adult mainstreamwebmasters.com is a board I recommend and post on.

Selling eBay with AdWords would put you in competition with a lot of big marketing companies with very deep pockets, eBay's as well, its and area I don't work in so I can't comment much.
My guess would be if you setup a site focusing on very niche areas and then link into eBay where they can buy the product you might do OK, but then again I really have no idea, I like easy money