There are millions of portal and millions more are in pipe line. Every one has brilliant Idea. to change the world.  The social networking portal are moving beyond just entertainment and connecting. There are now playing a role of mediator, broker, change maker, personalized to industry or the need.  There are thousands of needs and every need has at more then one competitor.  

People are just getting fragmented into various  competitive portals. and out of all those competitive portal, one portal is reputed, trusted  not because it is great in UI, or great in speed. but because authenticity of content.   

Content is the core of any portal. and there you must not cheat your visitor. let the content be less , but it must be authentic. this is only possible  by proper vigilance, there must be a way of verification of any content.  

  e.g in housing.com you don’t enter details of your house, instead just provide the address and contact number . some one from there office will physically come to your home take snapshot and upload all necessary details themselves. So no fake data.

e.g toptal, is one of the upcoming freelancer portal, but there you just cant join as freelancer,  you have to pass thru the process like any other company follows, interview ,test, bio data verification and what more. they says that only 3% of the people who applied for toptal are really allowed to join toptal.

So my best advise to anyone who has a brilliant idea of changing the world  is that avoid generating fake content. and filter all the content that are being put  on your portal. the only way is to  recruit people to do this. there is no automation beyond some level.