"In addition to more Tweeting, people who had more room to Tweet received more engagement (Likes, Retweets, @mentions), got more followers, and spent more time on Twitter. People in the experiment told us that a higher character limit made them feel more satisfied with how they expressed themselves on Twitter, their ability to find good content, and Twitter overall"-Twitter
It is important to note that those writing in Japanese, Chinese and Korean will continue to have a 140 character cap. It takes fewer characters in those languages to say something that would take many more characters to express in other languages.The new expanded character cap might not hit your device immediately. Be patient and soon you'll be tweeting all of your mind, not just half of it.

For most people, the new cap on Twitter is 280 characters
source: Twitter
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