does anybody have a idea why the prices for a click vary from 0.05 to 1.00 between, say google and mamma.com?
I can not see any quality difference between a client from there or there. However some people seem to consider it clever to pay 20 times more in google or overture.
Or may it be that some searchengine charge clicks that do not actually come from real searcher?
I have signed up for bizlivechat and find that 50% of my clicks come from some ip adress in seattle (tel provider) and the way these people navigate (or better do not navigate) over the side seems suspicious to me.
How can I avoid fraud from the various ppc companies? How can I controll the quality of a ppc (other than the conversion rate which is too low to be statistically significant)?
Ed

The difference in traffic or visitor quality between Mamma.com and Google.com is like night and day. That's why the price per click is so much different.

It would take too long to explain in detail why the quality is different. Basically, Mamma.com's level of daily visitor's is nowhere near Google's or Yahoo's and most of the visitors they do get are accidental. Mamma.com is a third tier search engine that uses second and third tier PPC systems that are desperate to have their ads shown anywhere they can. The result is their search results are not always very relevant and that's why fewer people go to them for search.

It's not "clever" to pay 20 times more at Google or Yahoo. It's necessary if you want to have the best chance to see some return on your investment.

What is smarter? To spend 5 cents per visitor and get 20 visitors in a week from a low quality source? Or to spend 50 cents per visitor and get 1000 visitors in a week from a high quality source? You don't have to be a rocket scientist to see which of those 2 choices is most valuable.

Of course, whether or not you make any sales once the visitor gets to your site ultimately determines whether the cost of the ads was worth it or not. Before doing any PPC advertising, we strongly recommend that you read the PPC Advertising article located in our Marketing Tips section and also the How To Sell Online article also located in the same section.