I'm not sure this is true. I had a one article blog where ads were approved. Though it had 800+ comments and ranked better than the thing it talked about (card options in an underbanked country where banks suck at making their products known). I'm almost certain very few of the people who got a card didn't visit the site(and it's the very reason I wrote it: it was hard to find any pertinent info in one place when I wanted to get a card that I felt the effort should never be repeated by anyone).