When people use ineffective hashtags on Twitter, it reminds me of the “Friends” episode where Joey didn’t understand how to use air quotes. He used them on random words.
Hashtags should only be used if they will bring your content to a wider audience or if they are necessary to track a campaign where you need to demonstrate ROI or create a reliable report about buzz levels.
Avoid trying to create your own branded hashtag, they rarely catch on. If you’re trying to create a trend, which could be possible at a large event like #SXSW, then research the different terms and see which phrases or words are already being used a lot. For any event, be sure to include the event hashtag in every tweet so it reaches event attendees as well as those following the event remotely.
Research your potential hashtags, pick one and stick with it if you want it to “catch on.” Pick something that already has a following and if there are none, separate out the words, like #autonous vehicles rather than trying to create a new hashtag that no one is watching.
Here was some research I did in on hashtags.org in preparation for CES: