A list-up of times used (30 days) for...

A list-up of times used (30 days) for hashtags associated with a searched term is a feature of something I'm making. If a tag has been used just once, from one account, I say its a "dead" tag, no need to list it. What do others think? Also, if a tag has been used in a number of tweets but all from one Twitter account, this, too, may indicate that we don't need to list it as a "relevant related tags" to the searched term. What do others think?