If you ever wonder if there is a potentially lucrative market for online video? It might be instructive to look to last week's purchase of Lightningcast by AOL.

Lightningcast is an online-advertising company specializing in the placement of streaming video and audio content. The deal will allow AOL to run targeted ads within broadband video and audio clips and dynamically switch out ads without having to pull the video file from the server.

Lightningcast handles advertising creation, insertion, ad campaign management and results reporting. AOL has had a working relationship with Lightningcast since 2002 and uses its services for AOL Radio, AOL Video and In2TV ventures.

In June 2004, AOL acquired Advertising.com for $435 million; and in January of this year, it purchased Truveo, the owner of a video search engine for a purported $50 million.

The Lightningcast deal was closed a week ago. Lightningcast's 34 employees will remain with the company Financial details of the deal were not disclosed.