What affects the location of Overture PPC ads on Yahoo? My ad has the 3rd place bid. Sometimes it appears in 3rd position above the organic SERPs, sometimes there are only 2 ads above the organic SERPs and my ad shows up as the top box on the right-hand side. The location seems to vary based on which computer I use to do the search, but does not appear to be related to screen size or version of IE browser.
Does any one have any data for CTR for 3rd position above the organic SERPs versus top box on the right-hand side?