Starting with iOS 7, Apple added a new "shared links" tab to its bookmarks in Safari. If you have a Twitter account connected to your iPhone, a tab in the bookmarks button called "shared links" (and marked with an @ symbol) will show you a list of links included in tweets by people you follow. In iOS 8, Safari no longer automatically asks Twitter for new links. Instead, it only looks for new links when the feature is actually invoked by the user. That meant million fewer MAUs are now counted for Twitter.JP Mangalindan, for Mashable
It’s good to know that Twitter counts people who don’t actively use Twitter in their monthly user counts.