Nielsen Online vs. ComScore search engine rankings?Yesterday, Nielsen Online released its September 2008 data for the Top US Search Providers.
Google came out on top with 59.7% and Yahoo came in with 18.1%. MSN garnered 11.8%.
This normally wouldn't have come as a surprise except for the fact that I recently learned that ComScore's September results differed as much as 3 percentage points. In its results, Google had 62.9% of the market share, Yahoo had 20.2% and MSN had only 8.5%.
I'm currently looking into the differences between Nielsen's and ComScore's methodology. More to come...