Elderly single people are lonely and looking for companionship. It's something more than friendship. Even if it's just that they get a dog, it's more than friendship.

And I think you can really only have one companion. It's similar to boyfriend/girlfriend/wife/husband.

Let me thesaurus this up.

Hmm...some suggest more than friendship (accomplice, ally, comrade, mate, partner, protector, consort, double, sidekick), others suggest perhaps less than friendship (associate, buddy, colleague, playmate, pal, roomie). But I wouldn't use "companion" to mean any of those less than friendship terms. Maybe this is the issue. Others use odd definitions.

Yeah, "longtime companion" has even more forceful terms (lover, partner, spouse).

Let me Google "companion vs friend".

Ah. That scholarly resource Yahoo Answers comes to the rescue yet again.

Companionship runs a little deeper then a friendship. Companionship is when a person is there with you all the time or very frequent. There's a deeper bond, trust, and understanding of each other. You go through and experiences things together and learn together. So it can be a spouse, a VERY close friend, or even a dog.

https://answers.yahoo.com/question/index?qid=20130513165319AAW478h

The Hindu basically agrees but adds the lesser "companion" definition too. They give Sherlock Holmes and Watson as an example of companions (i.e. they spend time together and are good friends) but go on "The word "companion" can also be used to refer to someone who accompanies you on a journey. You may talk to him, share food with him, but once you get off the train/bus, you may never see him again."

http://www.thehindu.com/thehindu/edu/2002/06/04/stories/2002060400030200.htm

I mean...yeah, a "traveling companion" is less than friendship. But that's a specific phrase and in that sense "companion" is used somewhat in jest.

On the other extreme, some black preacher totally disagrees that "companion" is higher than "friend".

Companions are friends who come and go but real friends stick by you like family.

http://drstacylspencer.blogspot.co.uk/2011/05/are-you-friend-or-companion.html

I totally disagree. I think that most people would place "companion" over "friend". Probably 80% of native English speakers would do this. But you're in the 20% so fine.