Stereotypes have some limited utility, because people who believe that stereotypes have value reward you for conforming to them, and punish you for deviating from them. For example, they may only market a product to you if you conform to a stereotype they have of people who would use that product, instead of materially analyzing whether the product would be a good investment for you and how to present the argument, which is harder than just going "you look like one of our customers, but your look isn't complete, let us fill that hole."

Of course, if what you're selling is a look and not useful for anything else, this is a good way to market, but if your product is useful, you can do better.

It's also important to add that CA's techniques didn't work.