- Last week, comScore reported that Yahoo beat out Google for the number of unique U.S. visitors during the month of July, but a closer look at the results suggests the comparison wasn't exactly "apples-to-apples."
- When comScore was tallying the 196.6 million unique visitors, the firm used census tags on the site that physically count each unique visitor; with Google, comScore used its typical measure of site traffic by estimating numbers from a panel of U.S. consumers.
- Nieslen data is derived completely from U.S. consumer panels and puts an even bigger gap between Google and Yahoo's traffic, with Google at No. 1 with 170 million unique U.S. visitors and Yahoo at No. 4 with 126 million.
From the article:
"That means that comScore may be able to provide an accurate tally of Yahoo's U.S. traffic but less so when it comes to Google and further means that stacking comScore's numbers for Yahoo and Google against each other may not yield an apples-to-apples comparison."