You seem to believe that only a corporation which owns the entire market is a Monopoly but it can be a lot lower
One of the ones I find most interesting is that of the Press. If my memory serves me well you have about 6 Corporations giving you your news and given that they all hold roughly the same views you are not getting a variety of views as would be expected in a democracy.
Obviously these things are important to all of us. Thatcher deliberately let Murdock in to buy the Times for the very reason that she knew she would be opening up the possibility of the Monopoly of our news which would mean we did not get other points of view.
This article points out how the Monopoly affecting Britain's news and media is also affecting our democracy.
Britain's media is owned by a tiny handful of corporations, with three companies controlling 90% of newspaper circulation – if we want a real democracy, it's time to break the power of the media moguls.
tribunemag.co.uk
and to put that onto a known use of these Media. The London School of Economics did a survey looking at how the Press spoke about Corbyn. They noted it was almost always offensive, most of it not true or a new and offensive description and none of it refuted. They thought such a one sided negatively slanted view of the Leader of the opposition was a direct attack on our democracy.