Reuters: Dish Network said that Comcast’s NBC is not airing ads promoting its Sling TV video streaming service in some markets. While NBC has banned Sling TV ads, other major networks such as ABC, CBS, Fox are running its commercials, Sling TV CEO Roger Lynch said in a blog post. NBCUniversal’s four locally-owned stations in New York, San Diego, San Francisco and Washington, D.C. have declined to air Sling TV’s ads, a spokesman for NBCUniversal said without providing a reason behind the move.