Traffic to Twitter was down a dramatic 27.8% between September and October, according Nielson and eMarketer. ComScore showed Twitter's unique visitors were down 8.1% in October and Compete reported a 2.1% decline.
But wide swings in Twitter use are common and any trend downward could also be attributed to increased use of third party apps and smart phones to access the service. The Nielson, Compete and ComScore measurements reflect unique web visitors. 18 million U.S. adults use Twitter.