Clickz: Averages Can Kill Your SEM Campaign

Kevin Lee does a great job here of illustrating why it is very dangerous to take averages at face value when executing SEM campaigns. In terms of cost-per-acquisition (CPA), too often people accept headline results without properly analysing the underlying data. Invariably, CPA will differ widely across the campaign. In order to maximise returns, marketers must track CPA at all levels.

Experienced SEM managers will know this. But with 85,000 advertisers using Overture, and 100,000 using Google, there is bound to be a high percentage that don't understand the need to look beneath the topline numbers.