Yahoo and Adobe are teaming up to deliver contextually relevant ads from Yahoo's inventory to PDF documents from a number of publishers. The ads will show up in a side panel to the right of the PDF content and are matched using keywords and analysis of associated concepts to keep them relevant.

Upon registering to use the service, publishers can upload their PDF content into Yahoo's ad serving system and then monitor the performance via reports. Publishers take a cut of the revenue and Yahoo will split its share of the proceeds with Adobe. Publishers participating in the beta include IDG's InfoWorld, Wired, Pearson's Education, Meredith Corporation and Reed Elsevier.

With PDFs being such a widely used document format, I'm surprised it has remained an untapped area for this kind of advertising. At this beta stage, the program will provide ads only from the Yahoo network, giving the company some open territory for its contextual ads ahead of rivals Google and Microsoft.