Yammer, a provider of private social networking platforms for enterprises, has raised $85M in a new funding round at a valuation that may be as high as $1B. Yammer, which has over 4M corporate users, competes with Jive Software (NASDAQ:JIVE) and Salesforce.com's (NYSE:CRM) Chatter. The startup recently announced its service would integrate information from SAP's ERP software.