????The market is not only ready, but demanding, says Whitely. "We've been shocked at how quickly this has been adopted. Not only that, but how aggressive our customers have been about what they want."

????However, the affiliation with another company could slow Chatter's spread, says to David Sacks, founder and CEO of competing software called Yammer. His model is to go in touting the best product rather than rely on a pre-existing business relationship. "Yammer can just spread frictionlessly across the entire enterprise," he says.

????Yammer is probably most dependent on its service spreading virally. The business model for Yammer is to release it, let consumers use it for free, then approach companies, point out that employees are already using the service, and offer to sell top executives special features and control.

????It's a "freemium" model, and Sacks believes it's working. He claims that Yammer has tallied 1.5 million users since it launched in September 2008. About 400 of the Fortune 500 companies have employees that use Yammer, he says, although not all of them pay. The rate for the fancy version of Yammer is between three and five dollars per user per month, although there's a discount for large corporations. He says that 15% of Yammer users convert to paying customers, which is enough, because the service sells itself.

????"We don't do any search engine marketing, we don't do brand advertising, we don't pound the pavement. It spreads completely on its own. When you have a zero marketing budget, then you can afford to be freemium."

????It's the same model that a company called Rypple is using. Rypple is a social software tool that facilitates employee feedback. The idea is that instead of writing performance reviews, employees will give constructive criticism or reward a job well done on a fast, webby platform, set up to host what co-CEO Daniel Debow calls "micro reviews."

????Like Yammer, the basic Rypple service is free, and people can pay for premium service. Unlike Yammer or Chatter, Rypple doesn't aim to reinvent the business social media platform. But it does want to squat on whichever company ends up dominating that space, says Debow. "I kind of look at the model of Zynga. I'm happy to be Zynga."

????Everyone in the space holds one belief in common—social media for enterprise will not be a work-friendly replica of Facebook and Twitter—it will not be a way to share cat videos colleagues. Instead, a successful platform will let you discuss documents, collaborate on projects quickly, and keep tabs on the CEO with the ease that you now tweet or read your friends' Facebook status.

????But whichever company dominates the space will need to create an app that still spreads like wildfire between users, because all successful social media does—and it's going to have to do that without the help of lolcatz. And though all these companies are nascent and perhaps easy to dismiss, it's worth remembering that Cisco, IBM, Microsft and Hewlett-Packard once were too.