I would even say that today advertising and marketing are the main components of the project’s success. If the team has a good marketer, it will be able to pull out the project even without technical innovations.
But this does not mean that innovation is not needed by anyone. Marketing really is the main component of success, but agree that if there is nothing to advertise, such an advertising company will fail. The product is equally important.
Ideally, there should be harmony. Only when sufficient attention will be paid to marketing and development in the project - then the project will be successful. It is always necessary to distribute your forces correctly.