What’s something insanely popular that you never see adverts for?

I had to sneak a Google search here, few that are surprising and I never clocked it. Some that are....stretching the truth somewhat. Zara never advertise, and thinking about it I've never seen a Zara advert. But they do rely on important city/town centre locations with massive and obvious branding, so that's *kind of* advertising. Tesla famously never advertise, which is one I didn't need to google, and until Musk became as popular as typhoid, managed to go from a laughing stock start-up to one of the world's biggest car companies. Rolls Royce don't advertise, though that's not surprising and technically not true. While they have zero need to run mainstream adverts given the price of their cars, they do cleverly place their cars at boat shows, as opposed to car shows, to make them look like more of a bargain to rich customers. I'm fairly sure they "advertise" quite hard among the aviation industry too. The most laughable one is GoPro. While they don't run traditional ads, they market themselves *heavily* by working with extreme-sports types and have cornered the action/minicam market as a result. Even TV shows like Top Gear/The Grand Tour used GoPros instead of specialist minicam companies, and some Hollywood films use GoPros (admittedly for a two second shot where the camera was likely destroyed). Thinking about it there's some companies I'm amazed even bother advertise. Surely Coca Cola, Tesco, McDonald's, etc are just wasting money?