NEW YORK — Most home Internet service providers offer unlimited data, but cable giant Comcast is moving in the opposite direction.
It has started charging heavy Internet users extra in more parts of the country. The reason? A small but growing number of consumers are skipping cable subscriptions and doing their TV-watching over the Internet instead.
So finding a way to charge for heavier Internet use could bolster Comcast’s revenue as the ranks of its cable customers shrink.
Comcast used to impose a monthly 250 gigabyte data cap on its customers, but ended it in May 2012 to experiment with alternative ways of managing bandwidth.
That August, it capped monthly data use for Nashville, Tenn., customers at 300 GB; going over the limit cost $10 for every 50 GB. The company launched a similar plan in Tucson that October — you got 300 GB for a base plan, 600 GB if you signed up for a faster and more expensive connection.
By December 2013, Comcast had rolled out the Nashville system to Atlanta and a handful of smaller markets, many in the South.
It also offered a slow Internet plan of 3 megabits per second that gave you a $5 credit if you used 5GB or less each month and charged you $1 for each gigabyte of data over 5 GB.
This month, Comcast added a tweak as it expanded the cap into Miami, Fort Lauderdale and the Keys in Florida: Customers can now pay an additional $30 a month for unlimited data. (In Atlanta, it’s $35 a month.)
At this point, about 12 percent of Comcast territory is subject to “usage-based pricing,” said MoffettNathanson analyst Craig Moffett.
The change comes as Comcast’s Internet customers grow and cable slips. In the third quarter, Comcast said Tuesday, it lost 48,000 TV customers while adding 320,000 Internet customers.
Revenue rose 8.3 percent to $18.7 billion in the July-September period, while net income dropped 23 percent to $2 billion because of a tax gain from last year.
The average household watches 240 hours of TV a month. Using streaming technology, it would exceed the Comcast cap by watching the same amount of online video.
About 8 percent of all Comcast customers go over 300 GB, the company says. Data caps really amount to a mechanism “that would introduce some more fairness into this,” said Comcast spokesman Charlie Douglas.
Yet Neil Smit, president and CEO of Comcast’s cable division, said in July that there are no plans to extend the caps “on a widespread basis anytime soon.”
