Probably because of the way government contracting works with (value added) resellers. One such is "Carahsoft" (see http://openbeta-contracts-explorer.usaspending.gov/#!/year/A...). If you dig into the details of the transactions you'll see that many are for technology companies' software and services. One example link that includes Salesforce, HP, VMWare, Symantec, etc.: http://openbeta-contracts-explorer.usaspending.gov/#!/year/A...