five years ago when facebook first went into public, its prospect is thought to be bad since the mobile wave is near and facebook's ad revenue mainly depend on PC side.

surprisingly,its annual revenue has risen from five billion dollars to thirty billion dollars in this five years. how does facebook succeed during its survival or death period ? what is its secret weapon ?

the answer is news feed . that is adding ads in our daily feeds.

the key strategy is accurate marketing. through facebook's big users' data base, it can match the ads with relative customers precisely .through CPM, the company can reduce cost while effectively advertising their business.

this helps facebook developing very fast.

but if we see this trend from world' view,will we be trapped in the our own information cocoon?