Freedom of speech allows business to promote their products.
One of the keys to why business in this country has been so successful is the fourth amendment protection from unreasonable search and seizure and the fifth amendment due process and private property clauses ensures that people will be willing to invest their money into a business knowing that the government won't be able to "nationalize" it without the business having committed some serious crime. This is one of the reasons why third world nations have remained poor - every time some business has some success and accumulates some wealth the "President/General Dejour" seizes it "in the name of the people" and funnels the proceeds into his Swiss bank account.
The sixth and seventh amendment right to trial by jury is the key to actually providing the protections of the fourth and fifth amendments. A government agency that would seize the assets of a business usually can't do so without a jury of citizens consenting to it.