Twitter isn't for everyone. While some may take steps to close down their Twitter accounts before saying goodbye, others simply walk away, never to return. On the other hand, many people use Twitter regularly without showing any signs of activity. Weeding out inactive accounts on your followers list takes a bit of detective work, but you can often spot them when you know what to look for.

Last Tweets

The date of someone's last tweet gives you a strong indication of whether a Twitter account is active. For example, if someone hasn't posted a tweet in over a year, and only posted a total of a dozen tweets, there's a strong likelihood that he's no longer active. If he posted a tweet in the last day or two, it's almost certain he is active on Twitter. Click on any name in your followers list to see when that person last posted and how many tweets he has posted since joining Twitter.

Dangerous Assumptions

While the date of a last tweet is a strong indicator of someone's activity on Twitter, this is not foolproof. Many followers may be using Twitter to read posts, even if they haven't posted in several months. On the other hand, if someone has set up an automatic feed for Twitter, the account may appear to be active even if the account owner hasn't logged onto Twitter in years. For example, if someone's tweets are all links to the same website, this may indicate the account is on autopilot, being fed only by an RSS feed from that website.

Profile Information

A blank profile page and the lack of a profile picture can be telltale signs of an inactive account. This is especially the case when the same account has not posted a tweet in a long time, or if there are no tweets on the account's profile page. When someone decides not to use a Twitter account anymore, but doesn't want to lose the username she claimed, deleting her profile information is one way of letting the account go dormant without actually closing the account.

Other Clues

Sending a tweet or a direct message to someone asking about them is a good way to tell if someone is active on Twitter. Give the person a few days to get back to you, since many people don't log in every day. Another way you may be able to distinguish between an active or an inactive account is to make a note of how many people the person is following. If that number goes up over the course of a week, for example, the person is actively using the account, even if he's ignoring your messages and not tweeting.