container as the content

In my opinion, choosing the right container is also as important as what type of content were being put into the container. It can determine how successful a message being conveyed to the audiences. I'm pretty sure this phrase is similar to the phrase coined by Marshall McLuhan which is Medium is the Message. For example if we want to advertise a brand new shampoo but we chose electronic direct mail as the container for the sake of the cost and getting the news spreading like fire in the most convenient way, will it able to convey its message to the consumers? How many percent of the consumer will actually view the email without flagging it as a spam? Isn't a tv commercial or a print ad would be more suitable as the containers instead of an edm? It is the container that will give the first impression to the audience.