Firstly, we don't need all these material things. Because developing countries or poor countries don't have all these goods, but they are happy.
Secondly, the companies brainwash and put their publicity in ours minds. They say If you have this car, you are cool... They push to buy, buy and buy.
To sum up, I need to say again that we don't need material things to be happier. We can search happiness in other sides and not shopping.