This is a simple, powerful, repeatable strategy: Tweet live during an episode’s first run. Tell your viewers about it with an on-air mention. (I like the Travel Channel’s implementation: clean and simple.) Then prompt them to tweet, too.
Very, very cool. Smart integration of Twitter, and the results of Twitter's media company outreach. There's a Fast Company article somewhere recently (too lazy to Google it) that talks about how they work w/media companies, so this output makes a lot of sense. TV commercials could learn something here.