We have always been truthful in advertising our products at a very modest discount below MSRP.
One of my Adwords competitors, is adverting 70% below retail cost, when in fact our prices are about the same in the end.
They ship directly to the consumer from Hong Kong, and have atrocious customer service, however they are a large company, with close to a 100,000 products.
They are not having much of an impact on me, but I was thinking of firing a shot across their bow with an Adwords ad that suggests for the customer to buy from us as a domestic supplier and that we dont use deceptive advertising, like the competition.
However Adwords may not be the forum for "in your face" comparative advertising.