As anyone familiar with my Web 1.0 research would know, I am very interested in the relationship between usability and marketing. If marketers really understand their users/customers from a deep usability (my research domain) perspective, then the line between the two fields really blurs.
For example, if I know that a customer is price sensitive when it comes to desserts (a marketing insight) and time sensitive when it comes to shopping (a usability insight), then presenting an ad for my low-price cookies in a way that is easy/fast to redeem and during the dessert-shopping activity, satisfies both goals. The customer doesn't see it as intrusive and frustrating (like the general population is starting to do with many ads these days) because it is a direct match to the current task and is customized to her personal preferences. Its not perceived as advertising but as assistance.
This comes to mind as I read an announcement in MIT Technology Review describing Microsoft's new business designing software for screens on shopping carts. Basically, the software would know who you are if you swipe your loyalty card and where you are in the store based on RFID tags. If you pause in front of the cookie shelf, it can present the ad I describe above. Of course, this only works if they effectively mine their loyalty card database well. If they present an ad for the expensive cookies to the price-sensitive shopper, it will be perceived as an annoyance. But I wish them well. When marketing becomes truly integrated with usability, we won't see another "ad" ever again.