The four-year-old San Francisco company has about 400 customers, all but five of which use the Leverage hosted service to provide public web-facing social networking tools to their users.

The remaining five customers use Leverage internally to help employees share information on a private network, and this is where chief executive and co-founder Mike Walsh sees an opportunity.

We’re seeing more and more of that. Right now we’re not very actively marketing directly to them, he said. [Sometimes] a CIO will call up and say they’re currently using X piece of software, say Sharepoint, and they’re looking for something easier for people to use and that has some social networking features.

In future, Walsh sees Leverage competing against the likes of Microsoft Sharepoint and IBM Lotus Connections, a possible replacement for enterprise collaboration platforms.

We don’t have wikis yet, and wikis are something pretty necessary to compete against these bigger players, he said.

A wiki, for those living still living comfortably in the Web 1.0 world, is a collection of user-editable web pages designed to help people share information and formulate a consensus on any given topic.

Walsh said he expects Leverage to have about 1,000 customers by the end of next year, about 20% to 25% of which will be enterprises using the service to help their employees collaborate.

The company is also planning to release an upgrade that will let these internal deployments connect their users’ profiles to Facebook, the popular consumer-facing social networking site, Walsh said.

At the moment, Leverage is mainly used by media or technology companies that want to create stickiness on their sites or cut customer support costs by letting customers help each other solve problems. Customers include Salesforce.com and the news site InfoWorld.

Features include user blogs, chat rooms and forums, scheduling and, in the latest release, social tagging and tag clouds – a keyword-based alternative to using search engines to find users or information.