The business instant messaging (IM) market will grow from 5.5 million users worldwide in 2000 to 180 million in 2004, a growth rate of 140 percent, according to a report from market analyst IDC.

By that time, the number of messages sent will approach two trillion annually, according to the report.

Technological improvements in IM software and new business processes are driving the adoption of IM, but vendors need to change the minds of knowledge workers and IT managers who see the technology only as a chat application, IDC said.

For instant messaging to succeed as a business collaboration tool, it will need to find a place to comfortably augment the dominant communication tool - email - not replace it, IDC said.

Groupware vendors are already embedding IM functions, presence awareness, and availability controls into their product lines. And availability controls are being built into the IM interface, allowing end users to find the most efficient way to incorporate the application into their workday.

The major growth barriers facing business IM are fickle end users, staid IT departments, and several competing unified messaging platforms, IDC said in the report.

Emerging technology is causing turmoil in the IM market at the moment, and success will come to IM vendors that are agile enough to adapt to the very rapid development of instant messaging, according to the report.