A Search Engine Watch Forums thread reports that Microsoft adCenter is inflating the conversion metrics by 30 to 40 percent.
Member, PPC, says:
For those that track conversions at MSN, does anyone else see inflated numbers? MSN consistently reports 40-50% more conversions than we are actually getting from MSN. I don't see how this is possible since the conversion code is only on our confirmation page and that page only displays for successful orders. Yet every day, MSN reports tell me that I have sold more units through this outlet than I actually have. Sometimes, one term will show 8 sales when in fact only only one unit of that specific product has been sold and there actually was only 1 click on that term!
Another member came in to confirm the same bug.
Forum discussion at Search Engine Watch Forums.