Have you noticed anything different about your Tweets lately? When I looked at Twitter earlier I spotted a new option underneath my tweets looking like the picture below. Next to the star for favourting a tweet there is a picture that looks like a little graph. When I held my mouse over it the text says 'view tweet activity'.
When you click on the image it pops up a screen which gives you brief statistics of that particular tweet: How many people saw the tweet, how many clicks it has had, how many times it has been retweeted and how many times people have clicked on the tweet to view it in full just like the picture below. It reminds me a bit of the Facebook 'reach' figure tht you get on the bottom of posts but with more information.
If you want to get more detailed information about the reach and interaction rate of that particular tweet click on the bit that says 'view details' in the bottom right corner. If you click on it you'll get a whole new screen pop up which shows you an hourly break down of the tweet impressions, as well as a further breakdown of 'key metrics' including faovurites, profile views, replies, shares by e-mail etc.
I think it's great that we can now see all this information at a quick glance it will make it much easier to see which tweets your audience best respond to, to ensure you deliver great quality tweets to your followers.