A collection of stats on SPIM and IM growth:

Marty Schultz

[from How to stop IM and SPIM abuse - News - ZDNet]

About 70 percent of all organizations used instant messaging by the end of 2003, according to market research firm Gartner Inc. Gartner predicts that by the end of 2005, instant messaging will surpass e-mail as the primary way people interact electronically.

All this IM growth is spawning rapid proliferation of SPIM, or spam through instant messaging. According to Ferris Research, more than 4 billion SPIM messages--will be sent in 2004. That's up 100 percent from 2003. The Yankee Group estimates that 5 percent to 8 percent of corporate IMs are SPIM.

Note: Marty goes on to make a number of pronouncements about IM use, most of which I profoundly disagree with.

"The final step in solidifying your organization against SPIM-based viruses is to centralize, archive and virus check all files being transmitted through Instant Messaging. [Ok] While there are several ways to accomplish this, most organizations have found that prohibiting files from being transmitted through Instant Messaging is the most reliable. The alternative, sending a file over e-mail, is just as convenient and easy as sending the file over Instant Messaging [no it's not]. Most IM management products provide a feature to prohibit files from being transmitted.