I should start by saying that I find ads incredibly irritating in any form. That said, Miele and DeLonghi are both more than a hundred year old companies. Maybe they don't need to advertise because they have such solidly establish brand identities, but they do advertise and they have advertised throughout their history as companies. Ads are a way of maintaining brand awareness, introducing new products, and creating demand. Even if you have an incredibly solid product with good word of mouth there is still benefit to advertising it.