[inigyou]

If advertising was banned I suspect the entire capitalism would collapse.

[ndriscoll]

Alternatively, products would be cheaper as we'd legislate away defection in that particular instance of the prisoners dilemma.

[inigyou]

There would be less products. Severely less. All drinks would be made by Coke, all potato chips would be made by Pepsi (who owns Lays). They would be much cheaper (or more profitable), and there would be no opportunity for competition ever again. Everyone who works for a company other than the above would be laid off because their company couldn't sell enough product to remain in business.