This is an important point. Readers should remember that what's obvious to them is not necessarily something "everyone knows" until it's pointed out. Personally I will say that when I first starting consuming movies at around age 20 I was not conscious of this dynamic, until I read about product placement in movies and then suddenly I started noticing it. Especially when a car chase scene goes into slow motion at just the moment that the camera gets a closeup of the tires and you can read the brand name...