If it doesn't look like advertising, you may actually respond to it.

I follow Chris Pirillo on Tumblr.  This was one of his posts.  It made me laugh.  Many companies use this marketing strategy.  If it doesn't look like advertising, you may actually respond to it.  Using an AI to predict what you'll favor based on past interactions has become commonplace.  Generating natural language so the communications seem familiar as if they comes from a friend, makes people more receptive to the message.  Most recommendations come from friends and family.  While you may not trust companies, you certainly remember and trust an old friend.  When you glance at an application and see, "Check out..." it's easy to assume that recommendation came from a friend.