One of the more difficult things to learn on Twitter is effective use of hashtags (check out this ReadWriteWeb article on the birth of the Twitter hashtag). Hashtags on Twitter today create hyperlinks for searches of tagged term, such as #sf, #sfgov, and #opensf. Clicking the tagged tweet leads to searches for #sf, #sfgov, and #opensf, while people searching for SF, sfgov and opensf will find the tagged terms and those same terms without tags.
Hashtags are frequently overused, used needlessly, and added to all proper nouns in a Twitter message, rendering them nearly unreadable. Conversely, they are often not used when they would be helpful for expanding the reach of a tweet or adding additional context.
The important thing to consider is using tags is the search result desired. In the picture above, a search for “OpenSF” turns up three successive posts, two to a blog link from OpenSF, another a tweet I sent using the hashtagged “#opensf.” A search for “#opensf” would turn up the tagged tweet alone. Because the tweets to the blog post include the name of the blog, there is no need to use the tag #opensf in the tweet. However, adding #opengov and #gov20 at the end of the tweet means it now ends up in searches for “opengov” or “gov20“ and in the results when people click those tags in others’ tweets.
In the same way, I often use the #gov20 tag at the end of a tweet that includes “Gov 2.0,” so that the post comes up in searches for both “gov20″ and “Gov 2.0″.
In posts from the San Francisco City Attorney Twitter account, I often tag tweets with #sf at the end, so that even if I’ve included “San Francisco” or “S.F.” in the tweet, they turn up in searches for “SF.” However, there is little reason to tag SF within a sentence, as it turns up in “SF” searches without a tag. In fact, by tagging a noun in the middle of a sentence, I undermine the tweet’s message, either by making it more difficult to read, or by giving my reader a hyperlink to click that takes them away from my message before finishing it. If I want the tweet to turn up in searches for “SF” and when people click the “#sf” in others’ tweets, I’ll add the tag to the end of the tweet.
Another important consideration in using hashtags to customize a search for an event or issue advocacy (such as our use of #opensf to share news relevant to this blog’s community) is to ensure that the tag is not already in use. Avoid tags that are already in wide and consistent use for other topics.
If you’re looking to integrate your tweet into searches for a broad topic, research which tags are most popular and where you would get the most impact. This is why I use #SF and not #sfo for City Attorney tweets. While some regions use airport codes as unifying tags, here, SF is the dominant term, while “#SFO” is mostly automated job postings and airport check-ins from Foursquare.
Finally, consider that when you tag a tweet, you’re piping it into search, and if you’re repeating a tweet, you might not need to tag it. The #gov20 and #opengov tags are pretty popular these days, some I often omit the tags in RTs to keep the search stream from getting more cluttered.
Any questions or comments about using hashtags? Have additional hashtag resources or tips and tricks that would be helpful to the OpenSF community? Let us know!