In our opinion, what distinguishes an "enterprise" social network from a "non enterprise" social network are things like:
1. LDAP/Active Directory support
2. Programmatic provisioning with an API
3. Support for integration with other enterprise applications via standard protocols. iCal / CalDAV for integration with calendaring servers / groupware, for example.
4. Etc.
like sharing an interesting link, a new library, sharing nice solutions, writing an article about how to use some new stuff on primefaces for example and so on
We're angling towards really large organizations with our offering - the kinds of companies that are using BPM / Workflow engines, a SOA architecture, LDAP/AD, etc. But many firms, especially smaller ones, might not want or need those integrations.
And smaller firms generally view 'Enterprise' solutions as bloated consulting-ware, so if that's their market, they need to work on their messaging.