Virtual data rooms let you store and access lots of documents in the cloud--thousands and thousands of them: Think souped-up versions of Dropbox for the corporate user.
Your customers would do complex transactions in which huge amounts of information change hands (think financial deals and lawsuits). Those transactions are sensitive and complicated, so virtual data rooms let users determine who is allowed to see what, and many provide detailed tracking services. They replace the physical "document rooms" that many law firms and financial companies used to employ during deals.
Now that nearly everything has migrated to the Web, VDRs have followed, servicing just about any industry that needs to share information with third parties. Big new users of VDRs include companies in life sciences, such as pharmaceuticals, as well as government and health care. The spike in bankruptcies, caused by the Great Recession, has also increased use of VDRs by the many parties involved in unwinding or restructuring corporate liabilities.