Founded in 1999, Lightningcast is widely-credited with pioneering the development of technology that inserts advertising into on-demand, live, and downloaded video content across the web.

AOL will use Lightningcast’s technology to run targeted ads within video. Lightningcast’s technology lets users change ads from time to time, without replacing the entire video file, and also insert ads into audio clips.

AOL has worked with Lightningcast since 2002, using its services for AOL Radio and AOL Video.

Lightningcast’s sales and operations will now be integrated into AOL’s Advertising.com business, which the company bought in 2004. Advertising.com’s newly launched pre-roll video network will merge with Lightningcast’s InStream video advertising network, and operate under the InStream brand. The combined network will comprise 300 websites and 175 million monthly streams.

In April, AOL received a Daytime Emmy award presented for content delivered via the internet, cell phones and other small-screen devices. The company’s online video technology was also behind 2006’s Live 8 concert. However, AOL faces stiff competition from Apple’s iTunes Music Store and Google’s Video service, which sells video clips of TV serials for $1.99 each.

Financial terms of the Lightningcast deal have not been disclosed.