Global CRM (customer relationship management) revenue grew 12.5 percent last year to $18 billion, a rate three times that of all enterprise software segments on average, as companies look to acquire more business and serve existing customers better, according to a new Gartner report. Salesforce.com overtook SAP as the largest single CRM vendor in Gartner's survey, with Oracle, Microsoft, and IBM following those two companies. SAP remained the top CRM vendor in Europe, however, according to the report, which was announced Monday.