If I'm going to buy say, a rain jacket, I haven't a clue what brands exist at high quality within my budget range, that's what the research is for.

Granted I won't buy a product from a brand that is completely absent from all of my research - reviews, online discussions, etc (could be Chinese rubbish or rebranded crap etc).

I'll find a brand that seems to be consistently good quality based on all the metrics that pop up in my research that best fit my needs, and add them to my short list if they have a product that meets my criteria.

But they don't need to advertise to me to accomplish any of that, they just need to be good enough to pop up favourably in my research locations.

Of course, reviews, discussion, videos, etc can all be faked, one just needs to sniff these things out where possible and take a leap of faith. If we choose not to believe anything we see or hear because technically it might be fake, we'll never get anything done, haha.

Good solid critical thinking does 98% of the work and has never steered me wrong.

Used before is way different than heard of. If I've used it before and liked it, sure I will favor that brand based on personal exp. If I didn't like it, of course I avoid it.

If I've only heard of it, that means absolutely nothing to me and I'm immediately skeptical. If someone has told me a brand is good, I'd consider it an informal review and it holds a small amount of weight.

Functionally, the brand is only useful for identifying and matching the products to the reviews and research I'd done on it, it's just a label.