Sure, advertising is profitable. Yet, there are various regulations or social norms telling what is available and what is not. For example, we can think of cove

Sure, advertising is profitable. Yet, there are various regulations or social norms telling what is available and what is not. For example, we can think of covering a landmark "because it is profitable" - e.g. think of dressing the Statue of Liberty in clothes of a given brand, or covering the Greek Pantheon in free-to-play game ads. Of course, tastes matter. The US is littered with (in real world) advertising banners, my native Poland - even more. But there are quite a few places in the Europe in which people would consider it off putting to use a glowing sign on a historical or otherwise clean design. So it is about both tastes and regulations. > most people are reluctant to spend money, but they're ok to "spend" their attention and their data This is a tricky part. Kind of miss times when we were buying paper newspapers. But let's take an example - devs were reluctant to pay $ for services. Not everyone and their dog pays for tokens.