I was the first to report that Twitter has begun showing some users how many views their individual tweets are getting:
Like many experiments in Twitter's continuous redesign, showing users what amount to pageviews is likely an effort to encourage people to tweet more. For users with a modest number of followers, tweeting can sometimes feel like shouting into a void. That's why Twitter started letting you know when someone favorites something you retweeted, or a tweet you were mentioned in — those moves help to build a feedback loop that still doesn't feel quite complete. A view count lets you know that even if you're not receiving retweets or favorites, your posts aren't going totally unread.