<a href="http://beyondbridges.net/wp-content/uploads/2011/10/dropbox.png"><img src="http://beyondbridges.net/wp-content/uploads/2011/10/dropbox-150x150.png" alt="" title="dropbox" width="150" height="150" class="alignleft size-thumbnail wp-image-851" /></a>

Other companies on the list; Facebook, Zynga, Groupon and Twitter are also on there for the same reasons. So rather than just question Dropbox – why not the others ?

Read more here : Is Dropbox Really The World’s 5th Most Valuable Startup?.

Business Insider estimated the value of Dropbox at $4 billion, based on its latest funding round at the end of August.