Receptional - 2:58 pm on Jun 23, 2003 (gmt 0)

I think we can agree that developing large numbers of low quality links develops largish numbers of low quality visitors. This can make a mockery of some pay per click calculations. Low quality visitors will have a significant affect on your perceived ROI. If site A gets twice as much traffic as site B, but only 10% more revenue, then they will erronously make a judgement about the average value of a visitor.

This value per visitor can pervade through your strategy, limiting your PPC bids, determining your banner ad strategy (what are they then?) and all other campaigns. If you haven't got your act together, the guy with half the traffic can easily start beating the other guy in terms of profits, by simply bidding on PPC correctly.

The trick, of course, is to then measure ROI by campaign or by search phrase, but this breaks down in the extreme. When you run hundreds or even thousands of search terms on PPC, breaking them all the way down to measuring ROI by search term is unrealistic, as the majority will show nil ROI on perhaps a dozen clickthroughs.

So - where should we go? how many visitors in a campaign of any sort is needed to have a statistically accurate sample size? and how do you segment your visitors into campaigns that allow you to work out proper ROI's?

Discuss?