User blog comment:Thewikilover/Dawnguard or Vampire? Which side has more benefits?/@comment-92.15.200.235-20120823212649/@comment-82.4.112.114-20120921214725

Because a licence for the content was added to the account you bought it on when you bought it. Whenever you buy something off almost any online service, they only let you use the content on the account you purchased it on. Sorry for the bad news ...