To that end, AppExchange was introduced earlier this year. It includes pre-built applications created by Salesforce.com and its partners. The stated goal of AppExchange, according to Salesforce.com officials, is to extend SaaS beyond CRM to finance, IT, human resources, legal, R&D, and other business software segments.

Sandbox will allow companies to download these applications and test them with their own data before going live.

The introduction of Sandbox also raises the bar for its competitors, according to Denis Pombriant, managing principal at Beagle Research Group. Pombriant said that in the future all SaaS providers "will be judged by whether or not they have this capability."

Features of Sandbox include a full production database copy, periodic refresh to keep the test bed in synch with changes to the production environment, and a "configuration-only" Sandbox that mirrors the production environment, but not the data.

Sandbox will be available as an option for the Enterprise Edition and will cost US$25 per month per existing Enterprise Edition user. The configuration-only version will be priced at $18 per month for existing users. It is expected to become available by the end of January.