Even though it’s pretty normal for initial episodes to be available in the form of a free preview as advertisement for premium subscription channels, HBO takes it a step further, and officially offers the first episode on YouTube in HD quality. Full episodes were available on HBO.com in the past, but with an additional registration/login step.
Even though it’s unlikely that consequent episodes will be available, it’s an interesting step towards more open social media promotion. And it’s certainly a great show.
More information on HBO.com.
(Update: Seems like embedding is disabled now)
