Almost any company has a facebook page.
And some places i worked at advertised it openly on large monitors and plasma tv's in the elevators.
Join us on facebook etc etc.

Myspace was a bit too early I guess.

Then along comes MMO's and Starcraft2.
Starcraft2 links to your facebook, its rough but it tries.

Wow has facebook achievement apps.

And now Rift has twitter achievements and Youtube uploads.

You can now create and upload videos from the game.

For the moment they are 3 mins and as high as 720p.