Things indicate that NBCUniversal has sold the premium generic domain name Sandbox.com to Sandbox Ad Agency.
Sandbox.com has been owned by NBC for sometime now but this morning I detected that the domain name has transferred out of brand protection registrar MarkMonitor to GoDaddy. Whois records do NOT indicate a change of ownership as NBC remains in whois records.
To note, GoDaddy is a registrar by default that allows one to transfer in a domain name and retain past whois