As of August 2015 Twitter ranks #2 in social media sites. Number 1 being Facebook
Follow the related link for the ranking.
There are many websites similar to Twitter such as Facebook and MySpace.
In this case, it's not a hashtag. It's actually a number sign. Twitter now displays the Google PageRank for each Twitter profile page. It should not be confused with a Twitter ranking -- people with lower follower counts can have better PageRank.
Facebook and twitter
cut off ranking
YouTube.comFlickr.comGoogle.comnews.bbc.co.ukcnn.comamazon.comlifehacker.comengadget.comvideo.google.comguardian.co.ukJustinsBlog.comThe above are the top 10 bookmarked websites which could be considered the highest ranking depending on the system of ranking. The last one is an honorary mention.The top 10 according to Alexa on this date:Google.comLive.comYahoo MailMySpaceWikipediaGmailYahoo SearchFacebookHotmailYahoo Japan
Twitter facebook clubpenguin
Movie star planet.com
facebook,twitter,tumbl'r -dateinsky
youtube, facebook, twitter, vevo
i think twitter
Schools block social networking websites.