AT&T is top business ISP, with Verizon second

Among large businesses, AT&T has a 28% share of Internet traffic

AT&T was the biggest Internet service provider for U.S. businesses in September, with 20% of the total business Internet traffic, followed by Verizon with a 12% share, online tracking and analytics firm comScore said Tuesday.

Even though those two companies controlled 32% of the market, many other ISPs compete for the business market and make it more competitive than the residential ISP market, comScore said in a statement. ComScore used browser-based Internet page views as its definition of Internet traffic.

CenturyLink, which merged with Qwest in April 2011 ranked third among business ISPs with a 7% percent share. Following the top three, TW Telecom, Level 3, and Comcast each had 5% of the market, while Sprint, TimeWarner Cable and Cogent each had 4%. The 10th largest business ISP was Cox, at 3%.

AT&T not only was the overall business ISP leader, the company had the lead in the separate markets, for small, medium and large businesses.

For large businesses, AT&T had a 28% share; for medium businesses, 24% , and for small businesses, 13%. ComScore noted that the small business segment is the most competitive, with 40% of the traffic handled by ISPs that rank below the top 10 carriers in that category.

On the large business side, comScore said the top five ISPs had nearly 70% of all Internet traffic in September. They were AT&T ( 28%), Verizon (19%), CenturyLInk (8%), Sprint (7%) and Level 3 (7%).

Matt Hamblen covers mobile and wireless, smartphones and other handhelds, and wireless networking for Computerworld. Follow Matt on Twitter at @matthamblen or subscribe to Matt's RSS feed. His e-mail address is

Copyright © 2011 IDG Communications, Inc.

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