Corporations take advantage of this the most, and the Reddit admins know about it and let it happen. You can actually pay someone running a service to get your post to the front page, and this happens every single day. All of the content is manipulated and artificially elevated/dropped. A big indicator of this is the glorification of the military and Obama/Biden - one look at r/politics should tell you all you need to know about how absolutely fake Reddit is now, and how much of a joke it has become.
RE: Here is how to manipulate Reddit posts in your favor(on a basic level).