writes "The Washington Post reports that 'Spim,' as people are beginning to call unsolicited instant messages, is the latest sign that online marketers will seek to take advantage of other communication tools, not limiting themselves to spam or pop-up ads. The good news is that it's not easy for spimmers to send unsolicited instant messages. Instant message providers like AOL, Microsoft and Yahoo have a lot of control over their instant message networks, and since they look at their IM offerings as gateway services that help draw customers in to their paid Internet offerings, these firms are already committing resources to making sure the spim problem never reaches the same scale as spam."
Even without the providers assistance, many people who use IM systems are smart enough to limit incoming messages to those from their buddy lists. Still, there must be enough of a success rate to move spimmers to continue messaging users.