A Salesforce.com deployment at travel company Carlson, announced Thursday, is a notable win in Salesforce's efforts to attract large companies to its burgeoning software developer ecosystem.

Still, Salesforce faces pressure to ramp up that ecosystem, with competitors working hard this year to topple the company's dominance in the market for on-demand CRM software.

Carlson, a $37 billion-a-year company with holdings that include Radisson Hotels, T.G.I. Friday's, and Regent Seven Seas Cruises, has deployed Salesforce's CRM software service across five of its operating groups.

But more significantly, Carlson also used Salesforce's Force.com platform to develop customized applications for the groups and has subscribed to software offered through Salesforce's AppExchange online store of on-demand software. Third-party developers using the Force.com platform create those applications. Carlson has subscriptions for Newmarket Commex, an event and meeting management app from Newmarket International, and CRM Surveyer, a customer survey tool from Vovici, among others.

"We explored a number of vendors in the market, but Salesforce.com and the Force.com platform stood out for its product breadth and rich functionality," said Anthony Forbes-Roberts, enterprise CRM manager at Carlson, in a statement. Forbes-Roberts couldn't be reached for further comment Thursday.

Force.com is a platform that lets developers build on-demand (or software-as-a-service) apps using Salesforce's own Apex language plus a development environment it calls Visualforce for creating user interfaces using HTML, Ajax, and Adobe Flex. Salesforce says more than 40,000 custom apps have been built using Force.com, cites more than 700 apps available from AppExchange, and claims more than 30,000 customer installs of AppExchange apps. Those apps are hosted from Salesforce data centers; AppExchange developers receive a portion of the subscription fees.

Despite the seemingly big adoption numbers supplied by Salesforce for Force.com and AppExchange, it's unclear how much these downloads are contributing to Salesforce's revenue base, as it lists all its revenue in one of two general categories: subscriptions/support or professional services/other. For its third quarter ended Oct. 31, Salesforce reported a net income of $6.51 million, up from $339,000 in last year's third quarter, and revenue of $192.8 million, up 48% from the year-ago quarter and 9% from the preceding quarter.

While those are good revenue numbers, the company's actual rate of growth has consistently declined in past quarters. Bigger competitors, including Microsoft and SAP, meanwhile, are working to ramp up their CRM on-demand offerings, which puts Salesforce under pressure to grow adoption of Force.com and AppExchange. Real revenue growth for those portions of its business will come from large deployments by big companies, such as Carlson.

Carlson used Force.com to integrate its enterprise applications, both homegrown and those from other vendors, to give users access to business information within its Salesforce apps, the companies said. Carlson also uses Force.com Mobile to extend this information access directly to its field staff.