Twitter is known to conduct trials of new features that may or may not be made available publicly. The latest experiment is adding view counts to tweets to let you know how many people saw a particular tweet. This will come in handy for businesses who want to see if their tweets are getting as much mileage as they assume. Advertisers were given first access to this but now it has gone live to other users. Twitter hasn’t indicated if they plan to roll this out for the entire user base.
Source: Ubergizmo