Mikk, you are clearly not a very good housewife :)

For then you would have a pantry, just buy things when they
are on special. So even if you buy an extra whatever, you are
still only using it, when you need it later on. So that is
a bit different to the Macdonalds story.

Supermarkets have their weekly loss leaders, which is what they
advertise in the papers, to get you through the door. Their
real profits are made by all those things that you buy, which
are not on special.

Now companies like Costco, take it to the extreme. Buy very cheap,
but you need to buy 30 toilet roles, or 10 kg of washing powder
or whatever. For of course it costs a supermarket significantly less
per roll, in labour terms, to sell you one pack of 30, compared
to 15 twin packs

Yes, mikk, I do feel manipulated.
Your key word was 'wasteful'. Good old western consumer ideology dictates that it's all there for the taking, and supermarkets would have to be the foremost purveyors of this extreme logic.
Although we delight in the knowledge that we have fifty brands of cereal to choose from, we forget that our choice of variety and type of shopping outlet has been whittled away for the most part to Coles and Woolworths. The same goes for the U.K. where Tesco's and Sainsburys reign supreme.
We are manipulated at their every whim. A trip to the supermarket is often a soul destroying experience - an automated reflex, certainly not one where the senses related to gastronomy have any bearing whatsoever.

Mikk,

This is done to shift excess stock. A smart consumer uses this to stock up on items he/she uses regularly.

Poirot, you sound confused. What on earth are you doing, going to
Coles or Woolies, if you hate them so much?

I remind you that there are over 1000 IGA stores in Australia.
You have butchers, fruit and veggie shops, speciality stores,
farmers markets, you can even grow your own if you wish!

I put it to you that supermarket chains grew, because examined
closely, they provide what consumers want, ie choice, convenience
and value for money, or people would not go there.

Yes the field narrowed down in the UK. The game is so competitive
that its fairly easy to go broke, trying to compete. Net margins
are slim, if you look at the figures.

What is far more dominant then food retailers, are global
food processors like Nestle, Kraft, Unilever etc. Buy your Uncle
Toby's and its Nestle at the controls. Unilever make a whole lot
of washing powders competing against each other. The list goes
on.

In the global scheme of things, these are huge coporations with
enormous power globally, Coles and Woolies are midgets.

It sounds to me that what you really hate is Western consumerism.
Fair enough, but it has become what it is, by people making
choices with their wallets. I can't see any reason to blame Coles
or Woolies, for giving consumers what they want.

I worry about it but like with the McDonalds example people need to thimk for themselves and resist such marketing.