Microsoft is expanding Office 365, its new cloud service for businesses, by adding new features, customers and markets.

Microsoft says it has added 30 new features to Office 365, including support for Lync for Mac and the ability to access and update documents in SharePoint Online in Windows Phone 7.5.

New customers include Campbell Soup Co. and Groupe Marie-Claire. Microsoft said Office 365 also will also be available for businesses to try in 22 additional markets today, including Argentina, Iceland, Indonesia, South Africa and Taiwan, bring the number of countries to 63.

Microsoft has a lot riding on the success of its new cloud service. It’s going head-to-head with Google and its Google Apps, also a cloud service for the enterprise sector.

Microsoft CEO Steve Ballmer introduced the cloud service in a June presentation aimed squarely at small and medium-sized businesses that don’t want to manage their servers.

Office 365 is sold on a subscription basis (or companies can connect Office software they already own to the cloud service) and includes Microsoft Office, SharePoint, Exchange and Lync.

“We are seeing really positive momentum for Office 365. Customers are adopting Office 365 eight times faster than our previous service, and the solution is on track to become one of our fastest-growing offers in Microsoft history,” Kurt DelBene, president of the Office Division at Microsoft, said in a statement Tuesday. “We are also seeing great traction with small businesses, with more than 90 percent of our early Office 365 customers coming from small businesses.”