External research report shows the benefits of Microsoft SharePoint over various Open Source solutions. Full disclosure : the report is sponsored by Microsoft.
IPED research shows that Microsoft collaboration-solution providers see larger, more numerous opportunities, faster growth, and up to 25-percent greater profit than competing providers who sell open-source products. And because Microsoft collaboration tools are pre-integrated, building a collaboration-solutions business around Microsoft SharePoint-based solutions can cost up to 2.5 times less than with separate open-source products.
Source : Microsoft.com