0 marketing (= encouraging people to buy a product or service) in such a way that people are not aware that you are trying to persuade them to buy it:
1 advertising a product in such a way that people are not aware that you are trying to persuade them to buy it:
Stealth marketing is not just an American phenomenon.
The company's experience taught brands either to shun stealth marketing, or not to own up to it.
Stealth marketing offers new advertising opportunities without adding to the interruptions by commercials.