I use Firefox with the anti-script and anti-ad Google plug-in ..
When shopping for some item I either go straight to eBay or to go direct to sites I have used before rather than use a search engine anyway …
I am well aware that on-line stores make payments to search engines and ‘price comparison’ sites to put them ‘top of the list’ .. and almost all price comparisons fail to take into account postage&packing or minimium order charges ..
So I would say no, Pay Per Click is a waste of money for most on-line shops ..