More than 21% of Americans—about 11 million people—use Instant Messaging at work, according to research conducted by those hard-working folks at the Pew Internet and American Life Project. The increased use of IM in the workplace (and in general) is partly a reaction to spam, which has rendered e-mail less desirable than it once was.

But with workplace IM comes the inevitable productivity complaint. The Pew study found that 40% of those using IM at the office send personal messages to co-workers and 33% to friends and family, while only 21% said they sent both personal and work-related messages.

My profound reaction to this (and to those who insist that these numbers support monitoring employee keystrokes) is: So what? Is every workplace phone call work-related? Every hallway conversation? Every e-mail?

Let’s skip the argument that an IM exchange will take a lot less time than a phone call and get right to the heart of the matter: Work is social. People will engage in social conversation whenever they gather in numbers. This is not a bad thing. It is through social conversation that alliances are formed, knowledge is channeled and resources identified. Besides, can you imagine how unengaging a workplace would be if there were no socializing? How motivating a place would that be? How much inspiration to excel is motivated by an atmosphere of drudgery?

Productivity in the information age is not measured by hours spent engaged in non-work-related activities, but by how much work is accomplished and how high-quality that work is. Quality of work might suffer if, say, a working mom is worried about her child left at home alone. But the Pew study notes that 22% of working parents like the fact that IM gives them with peace of mind by letting them check in with their kids from the office. In an AOL study, 71% of respondents said IM had had a positive impact on their work lives.

Communicators need to get more involved in the use of IM in their organizations, helping convey best practices, recognizing desired behaviors and applying the tool to their own communications. But the trend is clear. IM has become an integral part of the workplace communication mix.