As long as everyone understands that corporations and politicians for the most part are doing whatever is in their best self-interest (bottom line, political advancement or re-election, etc.), hearing that something is mis- or disinformation should be no surprise. At some point, however, they have to tell enough truths to be taken seriously. If they lied frequently, that eventually would be exposed, as Hot Rod is now discovering.
What I see more often is not out-right lying, but shading the truth a bit, or withholding negative information that would provide a more accurate/realistic view of an event or product, a la Kenobi's 'It's true--from a certain point of view.'