What about tv promotions using IM out, VoIP back?

At the CTIA show last week, digital advertising agency isobar's CEO Sarah Fay described a mobile marketing campaign her agency did for the tv series "Veronica Mars." (That's actor Kristen Bell, who plays teen sleuth Veronica).

Here's how it worked. Viewers sent SMS' to a specific address, and then those viewers received SMS' back from "Veronica." Those messages were sent during airings, and contained textual information about what was going on during the episode.

Fay said that within a few weeks, ratings doubled and the website associated with the show experienced a five-fold increase in page views.

I'm thinking this type of promotion could be done over an IM/VoIP connection, such as Skype, Yahoo! or Google Talk. 

Here's how it would work. A viewer could send an IM to a user name associated with a show. Maybe even a character,whose name would be reflected in the IM address.

The actor with the character could then reply at pre-set times via a phone call back to the IM sender. It could be any one of several messages that would be configured to be compatible with keywords included in the original message sent by the fan. And a pane on the IM window could also include an ad.

Am I on to something here?