YouTube TV is reportedly in talks with Vox Media, Brat TV and others to add free, ad-supported streaming channels -- a way to attract more streaming ad dollars while giving platform users cost-free value-added content.

The core technology needed to drive a breakthrough for addressable TV advertising exists, but industry cooperation is needed to "put the pipes together," say ad-tech executives.

Execs from top agencies weigh in on what's needed to accelerate momentum and spend levels.

CTV's share of impressions has been 35% or higher in each of the past five quarters.