The online video business is still suffering from a lack of premium supply, says Charles Gabriel, VP Video Sales at AOL. But that’s one of the reasons AOL Video continued to grow its platform and ad offerings this past year, he says in this interview with Ashley J. Swartz at the recent Beet.TV executive retreat.

As video grows, issues of viewability and pricing continue to be front and center, he tells us. “Viewability is a given when we deal with content syndication. It’s a given that it’s viewable,” he says. Maintaining a decent CPM is critical for the success of the business too, he adds. “[Last year] 27 billion ads were delivered in video, but when you talk about premium content, that doesn’t grow as fast, so pricing tends to go down, effectiveness changes based on environment and viewbaility becomes even more of a concern because money moves,” he says.

With its acquisition of this past fall, AOL Video has been growing its footprint in online video ads and is now serving ads that reach half of online video viewers in the U.S.

Gabriel recently expanded his role at AOL, taking on global video sales for The AOL On Network as of late last month. He also oversees the integration of into AOL Video.

Earlier this week, AOL said it had reached the top spot in comScore’s Lifestyle category with 33.1 million unique video views. Part of that growth comes from Makers, a collection of videos that has now surpassed 60 million video views.

For more insight into CPMs, viewability and video growth, check out this video interview.