If you use them, you will be using more time with your "friends" that uses the same tag(s) instead of enjoying your real Twitter stream.
For example, I started to use the Swedish hashtag #svpt because many other Swedes use it too. They even created a special web service for
it at http://svpt.nu/ ..
Then I noticed that I keep looking for new tweets with that hashtag via Twitter Search more often than my original Twitter stream!
Why?
I don't know. Probably because they where from the same country?
Then I noticed that I've got fewer and fewer new followers than I was used to every day.
Why?
Well probably because I was not so interactive with my other followers anymore!
Twitter is all about interactivity.
Let's put it this way: I have now around 100 Swedish followers and 800 from other countries. Which are most important?
All of them!
So I will stick to my stream from now on, and I think hashtags are only useful for marketing and to push content out to specific people.
For example, if I've written a Swedish blog post I could create a tweet with the #svpt hashtag to let the Swedish users see that, & they
could still interact with me via @replies, but I will probably never search for that hashtag again..
Another thing why hashtags is bad for Twitter is that they makes the actual tweet smaller. I mean, it looks really silly when someone puts
2 or even 3 Hashtags and almost no text in the Tweet!
Hashtags are bad for Twitter.
More about hashtags from the knowledgebase: http://cli.gs/hashtags
Follow me on Twitter: http://twitter.com/svartling
Buzz it!