What you're missing is the effect of brand visibility on people's internal thought processes. When you see something regularly, you internally gain a sense of p

What you're missing is the effect of brand visibility on people's internal thought processes. When you see something regularly, you internally gain a sense of permanence about the item as if it's a naturally-occurring part of the environment. This creates a floor for the brand's perception. It may not be a "I'll go out and buy it now" floor or even an "I'll choose that brand when a purchase decision is made" floor, but it will certainly be "I've heard of that brand" and possibly even "that brand is probably the market leader." For products which are undifferentiated, or for which buyers lack deep insight, that can be a strong advantage. It's also not an entirely logic-free assumption to make. If a brand can afford prominent and consistent advertising over a multi-year period then you can reasonably assume that it's making enough money to sustain its existence. That makes a costly, long-running ad campaign a decent proxy signal for market strength and/or social proof. Is it 100% accurate? Definitely not, but none of this behavior by the consumer or the advertiser is logic-free.