"Hashtags are worthless" ... for businesses trying to use generic keywords to drive engagement.<p>Who'da thunk it!<p>Yes, the content of `#marketing` is full of rubbish - go do the same search on Google and you'll see it is mostly SEO'd links.<p>But take a look at #RobotWars or #GBBO when those shows are on. It's a channel of like-minded individuals all participating in a shared experience. The same for a smallish conference. The event is a social object and the hashtag is the manifestation of people's delight.<p>Sure, you get the occasional spammer intruding, and a few companies fruitlessly trying to inject themselves into the conversation - but mostly it's just a global stream of consciousness. And I think that's very worthwhile.