NBCUniversal will allow advertisers to purchase some of its most expensive advertising inventory through a method that was created with the goal of making the price as cheap as possible.

The Comcast-controlled entertainment giant said it would make a portion of advertising across all of its broadcast and cable networks available for purchase via so-called “programmatic” technology, which helps marketers place ads according to a predefined set of data — and get it at what is believed to be a more efficient price. The technique is gaining more traction as Madison Avenue attempts to place advertising on TV in much the same way it does in digital arenas, with precision and in a way that can reach an audience more narrowly defined around a set of behaviors or characteristics.

The offering represents “a sea change,” said Dan Lovinger, executive vice president of entertainment advertising at NBCUniversal, during a conference call with reporters on Wednesday.

NBCU’s decision may cause some hand-wringing among media companies. Among many ad-sales executives, inventory purchased via “programmatic” means a bid to get a piece of ad time on TV for a less expensive price than might be had by other means.

“Not at all,” said Lovinger, when asked if NBCU was concerned that clients might be getting some of its best advertising real estate for a better price than the company might want to offer. Instead, he added, NBCU is responding to what its clients are seeking.

The announcement comes less than a year after NBCU’s parent company purchased Visible World, a technology company that helps advertisers place TV commercials across the country that reach very specific audiences. One of its early goals after being purchased last June was to place more emphasis on assisting advertisers who want to use predefined sets of data to align commercials with particular audiences and content.

This isn’t NBCU’s first step in these waters. Over the past two years, the company has made programmatic buying available to advertising clients for its digital video and display inventory. Others have experimented as well. In 2014 Disney’s ABC said it would test programmatic buying for online video inventory.

Under the plan, advertisers and media buyers would be able to develop ad schedules through a private exchange by using a combination of their own data, third-party data sources and NBCUniversal’s television inventory.

Advertisers do not have to buy a certain amount of ad inventory to gain access to programmatic purchases, Lovinger said.