Media ownership is a thesis all on its own, but the main things to remember about the press, are the political standpoints of the owners and the readers.
People buy a newspaper because it reinforces their world view, it feels like a friend that's on their side, that stands for the things that they think they stand for. If your political leaning is to the right then The Daily Mail, The Express, The Star, The Sun are all for you. If your political leaning is to the left then The Guardian, The Mirror, The Independent should be of interest. If you're vaguely undecided then have a look at the ever wavering Times.


Then look at the way that The Daily Telegraph (often referred to as The Daily Tory-graph) a right leaning paper covers the same story. This time Boys are being left behind... not celebratory, but warning of a disturbing 'gender gap'.
This is the same story, with the same figures, with the same information, presented in 2 different and opposed ways.
Where does that leave the interview that you're about to do?
Before agreeing to be interviewed ask yourself...
"Does this newspaper represent me or my organisation?"
"Does this newspaper have the same message we are buying into?"
"Is this the newspaper of choice for my clients, consumer base, customers, stakeholders?"
If not, then you may find that the interview will be more confrontational than you expect, it may even go down roads you don't want it to, especially if you're defending a politically left leaning action in a right wing newspaper.
What about journalistic impartiality?
When you're dealing with newspapers don't expect impartiality. They are there to serve a self selecting community of readers that have been drawn to that publication because they have their world view reinforced. Whether that world view is that women need more opportunity and university numbers signal a change for the better, or that masculinity is in crisis and boys need to be helped in the struggle to succeed because they are being let down by the left.
That said, news is news.
If you're asked to defend bankers bonuses, industrial accidents, killings, and embezzlement, no one will be on your side.
That's 'ownership' from the point of view of the intellectual ownership by the audience. Physical ownership will also have its effect on editorial, even if the papers protest that it won't.
If you are in competition with the owner of a newspaper, you won't get coverage, if you are in competition with the owner of a newspapers other companies, you'll get lots and lots of unwelcome coverage...

Wowcher is owned (at the time of writing) by DMG Media, who own The Daily Mail.
Groupon is not.

There are 11 pages of stories featuring or mentioning Groupon. Mainly very bad news about the website putting people out of business.
I wonder if there's a connection there?
Both physical and intellectual ownership will affect your message. It will affect how your message is spun, used, and in some cases abused. You always need to know what's going on behind the scenes before you become involved in sending your message out.