AOL had 61.5 million visitors versus nearly 61 million in September. Yahoo came in No. 2 with 56.5 million unique visitors, up from 52.7 million in September and Microsoft Corp.'s sites came in at No. 3 with 52.1 million visitors, up from 51.4 million in September.
Business-to-business and consumer sites broke into the Top 50 for the first time through online advertising campaigns and marketing alliances, Jupiter Media Metrix said.
In a research note, Merrill Lynch analyst Henry Blodget said the total time spent on the AOL Network was five times the minutes spent on Yahoo. He also said Amazon.com's shopping sites reached 17 million users and moved into No. 11 on the Jupiter Media Metrix's list.
Unique visitors are defined as the actual number of total users who visited the reported site at least once in October.