Soon to announce it’s “significantly beyond” the five million US sales it announced this April, internet video device outfit Roku is more than a box maker – it’s also trying to help its channel partners serve up sophisticated ads to those users.

“Advertising-supported apps are our fastest-growing segment on the platform,” business development VP Scott Rosenberg tells Beet.TV. “Every ad trading desk out there is serving in to Roku today.”

Rosenberg acknowledges ad-targeting data on connected TV boxes has not always been up to the same standard enjoyed by desktop and mobile devices: “Over the last 12 months, we’ve tried to raise the bar for the format.”

Old-style linear ads are apparently doing great – Rosenberg claims around 90% of the 30-second video ad spots served through Roku apps are watched in full. But the Saratoga, California-based outfit is also taking interactive-format ads from tech vendors like Innovid.

We spoke with Rosenberg at the TVOT show.