Even if Google (GOOG) is winning in the search engine market, Yahoo! (YHOO) does have the most unique visitors of any web operation. That may be changing as Google gains ground overall.

According to December comScore data, Yahoo! sites drew 136.6 million unique visitors in the US. But, Google was close behind at 133 million. Microsoft (MSFT) was next at 120 million followed by Time Warner (TWX) sites at 119.5 million.

With growing traffic at YouTube and Google’s search features, Yahoo! may lose its lead sometime this year.

Douglas A. McIntyre