But the company was reluctant to reveal the identity of the mystery customer, saying that it would disclose the details at a briefing in New York on Tuesday.
Salesforce did reveal that the company in question has expanded its Salesforce implementation from an earlier deployment of 1,800 users. The win was announced as part of Salesforce's fourth-quarter and full-year financial results.
The revelation prompted analysts to wonder how much impact such a large customer would have on Salesforce's revenue for next year, because large customers use the company'sat a heavily discounted rate.
Salesforce executives refused to release any details of the level of discounts offered to individual customers. Some commentators suggested that the mystery customer is Cisco. But Cisco currently has 15,000 users on Salesforce, which does not quite fit the position suggested by Salesforce management.
Currently, both Cisco and Dell are major Salesforce customers. Other recent major wins include Procter & Gamble, Societe Generale and Deutsche Bank.said in a conference call that the company gained "more than 250,000 subscribers" in the past 12 months.
The company now has 47 customers with more than 1,000 seat deployments, up 81 percent from last year, and 150 customers with more than 500 subscribers. According to Benioff, the company delivered 4.3 billion transactions in the quarter.
Total fourth-quarter revenue was $144 million, up 58 percent over the previous year, and up 11 percent over the previous quarter. Subscription and support revenue, key for an on-demand software company, was $132 million, up 60 percent from the previous year. According to Benioff, customer churn--the rate at which customers stopped using the service--was less than 1 percent in the previous year.
For the full year, the company reported revenue of approximately $497 million, up 60 percent from the same period a year ago. Subscription and support revenue was $451 million for the year, a year-on-year increase of 61 percent.
Colin Barker of ZDNet UK reported from London.