The hashtag has become universally recognized, for better and for worse. What's more, it's being used in ads, campaigns and plenty of places "in the real world."
That's great for Twitter, where the hashtag originated, or rather where it became popular, but it's a double-edged sword.
That's because others have implemented support for hashtags and the hashtag isn't always associated directly with Twitter in these ads, or in TV shows and so on, even though there is an obvious implied link.
Which is why Facebook is trying
to get in on the game. The rumor is that Facebook is working on adding support for the hashtag, that is, it will add a link to any hashtag phrases.
The idea is to help with discovery of new content on Facebook and bolster a global conversation, something the site isn't particularly good at, certainly not as good as Twitter.
Whether people will actually use hashtags on Facebook remains to be seen, Google+ supports hashtags and they are somewhat popular there, but Google+ has always been more like Twitter than Facebook has. Instagram supports hashtags as well.