That's an incredibly cynical way of looking at the situation. There is also the purpose of telling you about a product you can buy that might possibly be beneficial to your lifestyle. Through advertising you get to find out about that product faster, something especially important in these days of brisk innovation.
Here's the error.
Yes, they were products the target could have done without, but not something they can do without once they have the product.
Consider: The first iPhone. A device that opens possibilities to improve your life that never existed before. You could do without it, but once you have it you can't do without it.
I think you'd have appreciated an ad for the original iPhone if it eventually led to you buying one.
Like it or not, consumerism and capitalism go hand in hand. It has reduced global poverty and has made many of us in HN very comfortable. Advertising is bound hand and foot with this system. To deny this is to attack the very structure that we rely on.
( the above two paragraphs are possible satire )
Then again, maybe it wouldn't make a difference. It would be an interesting experiment nevertheless.