Showing positive attitude over twitter could increase your followers as well as your friends. Most of the user over twitter don't show positive attitude, but some are still there. A suggest by the twitter shows, how to show a good attitude by just using of ":)" wile tweeting, replying or ReTweeting.
Users over twitter always seeks for positive attitude. So, Twitter Featured it on their Real Time Search. If you are seeking for any positive tweet about anything such as news then you ma use "news:)" to result all positive tweets from the users.