Let’s imagine you’re a small or medium sized business and looking to use social software to improve communications on many fronts: support, service, marketing, etc. If you chose to use a service like Twitter, for instance, for some of this communicating, I can see the need to have a two-channel mindset: one public and customer-facing and the other private and business-facing. On the public channel, you’d talk with customers and prospects about the business, including everything from support help to promotional opportunities, to general good will. On the other channel, you’d communicate with people about the business itself, such as directing attention to important matters, or keeping track of employee activities, etc.
These could be all within a public system like Twitter, with the private channel activities being performed via Direct Message only, or the private conversations could be via a private platform like Socialcast or Yammer. The benefits to keeping them all in Twitter is a simple user experience for employees of the business. The downside would be