Comcast and NBCUniversal are partnering to use dynamic ad insertion in the MSO's On Demand programming. Dynamic ad insertion has begun rolling out in several Comcast markets, with plans to expand to the majority of Comcast markets in the coming year.Technology from BlackArrow's Advanced Advertising System allows ads to be changed or revised when necessary. Comcast will make the capability available to other programming networks on its systems in coordination with Canoe Ventures, which will also enable the capability to a broader footprint covering multiple operators by early 2012. Comcast Spotlight, the advertising sales division of Comcast Cable, is bringing dynamic ad insertion to local advertising clients as well.