Nielsen/NetRatings audience measurement data for September reveals that internet penetration exceeded 50% in twenty-one of the top 35 American local internet markets, reaching critical mass for the first time. Six months previously, only six local markets bettered 50%.

The city with the highest penetration is San Francisco with 60% of households claiming access to the internet via a home PC, followed by Seattle, San Diego, Portland, Oregon, and Washington DC.

The highest percentage gain, notes the report, was in New York, which led Philadelphia, Denver and Houston.

Nielsen/NetRatings attributes the record increases to lower cost computers and other user-friendly appliances such as digital TV and internet enabled cellphones.

News source: Advertising Age - Interactive Daily