New York - For the third month in a row, more Americans visited Yahoo's websites than Google's, according to comScore Inc.'s Internet traffic data for September.

The research firm said Monday that Yahoo Inc.'s websites had 197.8 million unique US visitors last month, while Google's had 191.4 million. Yahoo was ahead of Google in July and August, too. The last time that Yahoo was ahead of Google before that was in May 2011.

That said, Yahoo is still far behind Google in making money from the people who visit its websites. Research firm eMarketer estimates that Google will generate $38.83 billion in worldwide digital ad revenue this year, more than any other company. Facebook Inc. is at No. 2 with an estimated $5.89 billion, while Yahoo is No. 3 with $3.63 billion expected.