The ad can achieve magic if it's done up right. I once saw an ad on Ebay selling a folding work table and multi-tool thing which the guy said was the worst made piece of junk he had ever bought in his life. He went on and on about what a badly designed and totally lousy item it was, but did so in a very amusing way, including ancedotes about disastrous attempts to do craftwork using the folding work table and multi-tool thing.

It ended up selling for a surprisingly good bid...after attracting a quite extraordinary amount of attention for what was, essentially, an almost useless piece of junk. ;-)