A "#hastag" (for the majority of people in the universe who don't tweet) is a keyword that makes it easy to group a bunch of Twitter posts. So, the idea is that you can put this tag on the end of your, ahem, "tweet" like this:
@sassytweeter What's with Genevieve's skirt? Midlife crisis? #designstar
You can throw your comment into the pile and then search for the #designstar tag and see what other people are saying.
I have to admit this was the first time I noticed a #hashtag on a TV show, but it turns out a lot of TV shows are including a #hashtag on the screen. At last! I can be alone in a room, make snarky comments, and get the LOLs I deserve.
Except no one was watching...
Well, not no-one, but even a basic cable reality show should have more than half a dozen people posting, "I love that wall! #designstar." I'm sure that some shows are WAY more twitter-active, but I keep running into this lack of real numbers with big companies trying to leverage social media. Just the phrase "Leveraging Social Media" takes all the fun out of heckling...
Despite the lack of response for a mediocre reality show, I hope more shows promote #hashtags. It doesn't cost anything to put a #hastag on the screen, and when you have a show like The Secret Life of the American Teenager, it's handy to have someone define a #hashtag. (And, no, I'm not 14, either. I just picked it for it's extremely long title.)
Ultimately I feel that putting the #hashtags on the screen as planting little social media seeds -- people will still use the corporate tag when the show isn't on, so the marketers can keep an eye on twitter chit chat and tweeters can find each other.
What those seeds grow into remains to be seen -- I did see that someone was tagging The Secret Life of the American Teenager with #thisshowsucks.