With most TV viewing on mobile devices and tablets occurring in homes, TBS and TNT have started getting positive results from a new tech tool that enables viewers to “cast” programming they discover on mobile devices onto their big-screen sets.

Working with emerging tech firm Vizbee, the Turner networks quietly have implemented the feature and registered a 30% month-over-month gain in the number of “casts” between June and October. Jesse Redniss, chief innovation officer at Turner and TBS, offered a closer look at the service during a session at the TV of Tomorrow conference in New York.

“People are mobile and out and about, but when they settle in to watch longform content, they are usually doing it in the household,” Redniss said, noting research estimating that 82% of viewing on tablets and 64% on smartphones occurs in homes.

Describing Vizbee as “Chromecast on steroids,” after the Google streaming device (which accounts for 88% of engagement), Redniss described how it has racked up 1.7 million “casts” to date. Many of those came during Major League Baseball playoff games in October. The company plans a major push of the feature in the first part of 2018, especially during the NCAA men’s basketball tournament. Turner shares rights to March Madness with CBS and will broadcast the championship game.

Casting of TBS and TNT fare is now possible via Roku, Amazon Fire, Apple TV and Samsung smart TVs.

By design, the service has flown largely below the radar in 2017, Redniss said. “The organic marketing approach was to do posts saying. ‘The score of this game is really close, you should check it out,'” he said.

The strategy will become more meaningful, Redniss argued, when the network dials up its effort to push viewers to cast major linear premieres for shows such as TNT’s upcoming The Alienist. There is an upselling opportunity with Turner advertisers, who might be willing to pay more for ads that are served on big screens given those are considered to be higher-value impressions compared with mobile or social ads.