It is a well know fact that it is dramtically cheaper to keep an existing customer happy than it is to attract new customers; at the same time it can be much more difficult to repair the relationship with a customer you lost than it is to find new customers (depending on the reason the relationship was damaged).
The job of marketing is to attract new customers, and to keep existing customers happy ... The job of PR is to repair the relationship with your existing customers.
Sony's PR is working overtime lately because existing Sony customers who own a PS2 are choosing Sony's competitors products (the Wii and DS) at an alarming rate for Sony; they want PS2 owners to believe that the Wii is no fun, and go out to get a second job so they can buy a PS3. If they don't stop the flow of gamers they will have an uphill battle to ever sell a PS3 to a lot of these gamers.
