More than a third of people on Facebook have their cellphone up there and that's something that's useful for the application.

事实上，超过三成的Facebook用户,都公布了自己的手机号,所以这个应用程序对于我们来说,十分重要。

扎克伯格谈Facebook创业过程课程节选 : 斯坦福公开课