After at least two years of testing the ability to dynamically insert ads in on-demand content, Comcast is set to commercialize the service, placing ads in shows from several NBCUniversal networks.

Comcast said it has already begun rolling out the capability and should have it available in the majority of its markets "in the coming year."

The first on-demand content to get ads in the Comcast system will come from USA Network, E!, Syfy, Bravo Media and Oxygen Media. Content from other NBCUniversal networks is expected to be added to the service in the coming months.

The two key advertisers will be Chrysler and Kraft.

Initially, inserted ads will be entirely pre-roll and post-roll. Mid-roll ads will be introduced later this year, Comcast said.

The MSO did not say in which markets dynamic ad insertion in VOD will first be available, but the company did provide some hints. Comcast's first trials of the underlying technology were in Jacksonville, Fla., in 2009. The MSO also said that Comcast Spotlight customers will also be able to take advantage of the capability, and many of the partners listed are in Florida and in Richmond, Va.

The list includes South Florida McDonald's, Richmond's nTelos, Virginia Credit Union, NBC12/WBBT-TV and Batteries Plus.

Comcast also said it will make this capability available to other programming networks on its systems in coordination with Canoe Ventures, which will also enable this capability to a broader footprint covering multiple operators by early 2012.

On the technology side, Comcast has been working with BlackArrow, using that company's Advanced Advertising System since before the Jacksonville trial began.

Though other MSOs, including Bresnan Communications and Cox Communications, have been experimenting with the capability, dynamic ad insertion in on-demand is thought to be contingent on big numbers (see “Giving VOD advertising the business”).

Comcast has reasonably large numbers, including more than 22 million subscribers, more than 20 billion views of on-demand since the service was launched in 2003, and a current average of 350 million views per month.

"On-demand programming is a key way to reach today's consumers and an important part of an advertiser's marketing mix," said Ed Swindler, executive vice president and chief operating officer for NBCUniversal Advertising Sales. "This capability helps make the service more advertiser-friendly, giving clients greater flexibility to ensure their ads remain timely and relevant."