Salesforce said Monday afternoon that it is buying BeyondCore, a San Mateo data analytics startup that raised about $9 million in a Series A funding round two years ago from Menlo Ventures. No price was given but at least one analyst questioned whether Salesforce CEO Marc Benioff's recent mergers and acquisitions spree will have an effect on the company's returns. "(Salesforce.com's) pace of acquisitions clearly raises concerns about its ability to grow margins meaningfully from the current level,"...