The interesting thing about Google's new free email service is this line from the article about it on CNN: "To finance the service, Google will display advertising links tied to the topics discussed within the e-mails. For instance, an e-mail inquiring about an upcoming concert might include an ad from a ticket agency."

Unlike, let's say, Hotmail where there is a random ad tacked on to the bottom of the message, Google will be categorizing unstructured email content and attaching the appropriate ad in real time.

DSBPI thinks that this should be the business model for IM as well, where the IM engine would categorize your chat sessions in real time and display the appropriate ads in the window. Let's say DSBPI IM'ed its broker and asked: What is MSFT trading at? The engine should immediately present ads for TD Waterhouse, etc.

Perhaps Google's mail program will go some ways in allaying privacy concerns on this model. Or maybe Google will have to be the IM vendor that rolls this out.