I think for luxury brands advertising is even more important. Because they need to justify the inflated value of their brand.
Consider a Ferrari or a Rolex. It's not as much value for money as a cheap car or watch. There's some workmanship sure but most of the increased cost is just perceived value. People buy them because they are expensive, so they can show they have money. That only works if everyone knows it is expensive and the product has a good name.
Cheap stuff sells anyway because people need it and it is the best value for money.
Consider a Ferrari or a Rolex. It's not as much value for money as a cheap car or watch. There's some workmanship sure but most of the increased cost is just perceived value. People buy them because they are expensive, so they can show they have money. That only works if everyone knows it is expensive and the product has a good name.
Cheap stuff sells anyway because people need it and it is the best value for money.