When people search Pepsi Cola they expect to get a link to Pepsi or information about it. They don’t expect to see Coca Cola or RC Cola, etc. now in this case Pepsi makes sure search isn’t polluted by paying Google good money to always be the top results for that term.

Now, if you searched on the generic ‘cola’ or ‘soda pop’ then yes you expect to see those who bid higher to be at the top and at the bottom those who bid nothing unless organically somehow they ended elsewhere.