the hard part is to know which of the products can be advertise in order to get a good ROI, if any, when choosing to spend on ads rather than ebay fees that could've been spent.
Are you familiar with any technique of choosing that right products that should be safe to advertise, rather than trial and error? I would be glad to hear.
People use ebay search engine to find products they wanna buy, while in google this is not always the case. IMO the proportion between views ans sales are much better than you would get on google or facebook ads, but again I might be wrong.