Mashable made its readers to identify the most popular posts or topic of their blog. They put forward a box at the top which is showing "Now Trending". They put forward their best and popular post on that box to make its users read that post first because it contains the featured writings. Earlier the users used to face problem over Mashable to find the most Featured post as in blog the posts comes one after one which makes the featured posts down after the newly post update.
Most of the mashable readers are now enjoying this new adding of this new box.I think they arrange the popular post on the basis of the amount of "retweets" and little bit of facebook "Shares". This Trending topic is the concept taken from Twitter trending topic... Even i loved this new idea of showing the trending or host post as mashable publish more than 25 posts daily and from them to find the best content is now easy.