The latest service to enter the online video advertising space is due to launch today - and it's all about text.
Adap.tv analyses the content of video clips, finds related text link advertisements and overlays them on the footage.
Launched by Amir Ashkenazi, founder of Shopping.com, the service is among the first platforms to take contextual advertising in to the video realm.
It employs speech recognition technology to serve up ads related directly to the clips being shown.
Adap.tv has struck partnerships with Amazon.com and Shopping.com that allow ads to display links to items from the etailers' product catalogues.
A video of Letterman interviewing Tom Cruise might show a link to buy a Mission:Impossible DVD, for example.
Adap.tv says it will give advertisers access to reporting tools with which they can customise ad placement, outlets and their marketing spend.