Searching for hashtags is a common method of finding new leads on Twitter, but tags in tweets can be misleading. Sarcasm and irony are so often used in tweets that finding a tag doesn’t tell you if that user is for or against the tag’s meaning. In fact, tags are often used in tweets to make sure the opposite side sees the tweet in search. It is a way of saying “in your face” in a tweet.
A much more accurate indicator is the use of a tag within an account description. After this last Super Bowl, I’m sure lots of Seahawks fans sent derisive tweets with the #broncos tag, but I doubt if any of them put #broncos in their account bio. From my experience, a tag used in an account bio is the most accurate way of qualifying a lead for any issue.
My Engagement Programming book has a couple of scripts that can help you find the most popular tags for any subject. You can use this script to extract all the tags found in user descriptions you have collected with the API, and this report to see which tags are most popular.
Once you have identified the best tags for any subject, you can qualify a list of users by finding those who have these tags in their description.