Lightningcast announced plans to create a web video network to allow advertisers to run internet video ads on small-to-midsize websites, AdWeek reports. Called Instream, the network intends to provide smaller publishers to tap into the growing demand for online video advertising, and it will begin to sell ads in September. Lightningcast plans to allow advertisers control over where their ads appear, with clients choosing individual sites or categories. For the most part, Lightningcast will show 15-second video ads.