Because I am an engineer and I battle distractions all day, I have always thought of hashtags as Twitter's dumbest feature. Back when Twitter was new it took me weeks to understand just why people were complaining about spammers. How could you be spammed on Twitter? I asked myself. Shouldn't you just unfollow the spammer and get on with your life?

But since then I have had the occasion to witness marketers using Twitter. And I have learned that, to a marketer, hashtags are pure heroin. You get to eavesdrop on strangers discussing products. You can count references to your product, and to your competitors' products. So what if this activity bears the same relationship to actually getting out of the building that playing Rock Band does to a real blues jam? It's a rush, and it comes in optimal tiny doses like Snackwell cookies, and it almost feels like productive work. From what I can tell a majority of the marketers in the world have Tweetdeck open all the time and wince reflexively every time anybody on Twitter says anything bad about their pet trademarks. To ask them to do otherwise is like asking a novelist to stop compulsively reloading their Amazon sales rank over and over.

Without hashtags, you can still do most of this with regular ol' keyword searches. So I think search is your real enemy here, not hashtags.

Yeah, folks at my company follow discussions about our products on Twitter and it doesn't matter whether the person uses a hashtag or not. What you need is a distinct product name though, to only discover relevant tweets.

Hashtags make it easier, sometimes people don't provide enough context or use the same words you would for a product or service, if people start using a common hashtag it makes it a lot easier.

An example of this that I used a bit in my thesis (admittedly not product based) was the #ausvotes hashtag for the Australian elections. There were plenty of Tweets that would have been very hard to identify as related to the election without that hashtag because they were mostly thoughts or opinions without context.

For a while now I've thought it would make sense to create 'relevant trends' for users - take the people you follow and the people they follow, and generate 10 trending topics From those people's tweets. Trending topics would become so much more useful.

This. I don't think people realize that (I hope) most of Twitter's users are interested in specific people, not the generic Twittersphere.

I find the trends offensive; as they seem to suggest that it'd be better if I talked about a certain topic, which is often terribly banal and uninteresting. Mostly because I believe the last thing the world needs is yet another mechanism to shove popular culture into people's faces: if it was so good, it wouldn't have to be hyped as much.