Following a trial in several markets, Comcast has begun the commercial rollout of a usage-based data policy that limits usage to 1 Terabyte (1024 Gigabytes) a month before customers are charged $10 for each additional bucket of 50 Gigabytes.

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Per the current policy, those overage charges will not exceed $200 each month no matter how much data a residential customer uses. Comcast, which is also giving customers two courtesy months before data overage fees would be applied, stressed that about 99% of its customers don’t use more than 1 TB in a month (with median usage of 75 megabytes). Comcast also provides an online tool/meter that shows customers their data usage. Comcast also sends customers an in-browser message and an email when they are approaching or have exceeded 1-TB of usage. Subs can elect to receive those messages, or a text notification, at 50%, 60%, 70%, 80%, 90%, 100%, 110%, and 125% of 1-TB. A notification will always be sent when a customer reaches 100% of the monthly data plan.

While critics have held that usage-based broadband policies can help cable operators keep OTT video competition in check, Comcast reiterated in its FAQ that its data plan “is based on a principle of fairness….Those who use more Internet data pay more. And those who use less Internet data, pay less.”

In markets with a data plan, Comcast is also offering an unlimited data option that costs an additional $50 per month, which is higher than the fee of $30 to $35 per month, depending on the market, that the operator had previously been testing.

For light Internet users, Comcast also supports a “Flexible Data Option” for customers on its Economy Plus and Performance Starter high-speed tiers that provides an automatic $5 credit if their total monthly usage is less than or equal to 5 GB per month. On that plan, Comcast charges $1 for each 1-GB of data used over the 5 GB threshold.

Per the FAQ, Comcast’s Terabyte usage plan is active in the following markets: Alabama (excluding the Dothan market); Arizona; Arkansas; Florida (Fort Lauderdale, the Keys, and Miami); Georgia (excluding Southeastern Georgia); Illinois; Northern Indiana; Kentucky; Louisiana; Maine; Southwestern Michigan; Mississippi; Tennessee; Eastern Texas; South Carolina; and Southwest Virginia.

The plan is set to become effective November 1 in these markets: Alabama (Dothan); California; Colorado; Florida (North Florida, Southwest Florida and West Palm); Southeastern Georgia; Idaho; Indiana (Indianapolis and Central Indiana; Fort Wayne and Eastern Indiana); Kansas; Michigan (Grand Rapids/Lansing, Detroit, and Eastern Michigan); Minnesota; Missouri; New Mexico; Western Ohio; Oregon; Texas (Houston); Utah; Washington; and Wisconsin.

Comcast markets in the Northeastern U.S. and Mid-Atlantic region, including Washington, D.C., are not yet part of the data plan rollout. Comcast has not announced if it will expand the policy to those areas.

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Comcast’s data usage plans don’t apply to Comcast Business Internet subs, customers on “Bulk Internet” agreements, and customers that use the MSO’s new Prepaid Internet service (offered in a handful of markets), or its FTTP-based Gigabit Pro (symmetrical 2 Gbps) offering.

The FCC is looking into data cap and zero-rating policies, has not set a timetable on when the Commission would complete its review.

To give customers a sense of how much data 1-TB is, Comcast’s FAQ notes that it’s roughly equal to streaming 600 to 700 hours of HD video, playing online games for more than 12,000 hours, or streaming more than 15,000 hours of music.

Comcast also posted a video to illustrate 1-TB. Watch it below.