http://clickequations.disqus.com/Paid Search Marketing and AnalyticsenWed, 29 Oct 2008 13:24:19 -0000http://www.clickequations.com/blog/2008/07/keyword-click-through-rates-ctrs/#comment-3365739One additional factor might be the consistent over-reporting of impressions by Yahoo (or failure to remove robot traffic) as we found here; <a href="http://connect.icrossing.co.uk/icrossing-update-google-ctr-x3-higher-yahoo_639" rel="nofollow">http://connect.icrossing.co.uk/icrossing-update...</a><br><br>Admittedly, we are reporting averages - but we are clear that they are averages across hundred of thousands of keywords.<br><br>R.e. "We know different text-ad copy produces different CTRs"<br>Optimisation of Ad copy via decent statistical analysis is an under-used activity, and one that pays off almost immediately.David Hughes Head of AnalyticsWed, 29 Oct 2008 13:24:19 -0000