AT&T drives most Internet traffic for US businesses in September 2011

CenturyLink, which merged with Qwest in April 2011, ranked as the third largest business ISP at 7% share. The five largest business ISPs drove nearly 50% of business Internet traffic across the US.

"The current state of the domestic business ISP market reveals a landscape led by a couple of top providers. However, even with smaller carriers contributing only a fraction of the traffic delivered by top carriers, the business ISP market is still more competitive than the residential ISP market," said Greg Mishkin, comScore vice president of telecom and wireless. "The small business segment is even more competitive among ISPs, highlighting the need for providers to develop strong marketing strategies to ensure they can retain and grow market share."

Business ISPs see increased competition when catering to smaller businesses

A more detailed look into the business ISP market according to the size of businesses being served also reveals AT&T to be the leading business ISP in the large, medium and small business segments. In addition, the top five ISPs accounted for nearly 70% of all traffic in the large business segment in September 2011, showing a high concentration of the top providers. In contrast, the share of traffic driven by the top five ISPs was significantly lower within the medium (56%) and small business (40%) segments.

The small business segment has proven to be the most competitive for business ISPs, with nearly 40% of traffic driven by ISPs that rank outside of the top ten carriers for this segment. While AT&T continues to lead all ISPs for small businesses, its 13% market share is significantly lower than its share in the large and medium business segments. Comcast (8%) and Verizon (7%) rounded out the top three ISPs in the small business segment.

*Based on the number of employees per business

AT&T and Verizon lead among business ISPs in the top ten US local markets

An analysis of the top ten US local markets shows AT&T holding the top position in the majority of these markets in September 2011. Verizon led in 3 of the top 10 markets, including New York, the country's largest local market. Similar to what was observed at the national level, the competition for business ISPs increases among smaller businesses. In the small business segment, Comcast and AT&T each ranked as the top ISP in 4 of the top 10 local markets, while Verizon and Cablevision each led in one local market.

*Based on the number of employees per business

AT&T drives approximately 30% of financial services and healthcare business Internet traffic

An analysis of the business ISP leaders for different industries revealed AT&T drove approximately 30% of traffic in the Financial Services and Healthcare and Medical industries in September 2011, showing a notable lead over other ISPs. In contrast, the Telecommunications and Software and Technology industries showed greater market fragmentation among business ISPs, with the leading providers driving less than one-fifth of traffic in these markets, followed closely by their competitors. Verizon and CenturyLink/Qwest ranked among the top three business ISPs for several industries as well.