Family, friends, people living in the neighbourhood of your business. If it's any good, it'll spread. If it isn't, it doesn't deserve to spread.
> What is the shop owner incentive to promote your product this way before he can be sure that he will sell some of your stuff.
It can be either way for the shop owner; your product might turn out to be a flop, or an overnight success. Stocking shelves is an active process, an exploraition vs. exploitation problem.
> Your local car manufacturer?
Word of mouth. Regular (i.e. not rich) people don't buy cars off adverts, they buy off experiences of other car owners. This works well enough in practice already.
> Without ads, how would those magazines be monetized?
Companies would pay to be put in them, obviously. Also, without ads being prevalent everywhere, people might even be inclined to buy them. The difference is, it would be people who choose when they see ads, not the advertisers.
> SEO = Marketing
SEO == fucking up the Internet by greedily exploiting imperfections of search engine ranking algorithms. It is indeed marketing, and something I'd love to see disappear. I hate SEO, and have been on the receiving end of SEO practices (i.e. blogspam) in the past.
How do you win your first few mouths?
> I could walk around the shop and discover a new product on the shelves.
What is the shop owner incentive to promote your product this way before he can be sure that he will sell some of your stuff.
> Or, pick up a catalog with local companies.
Your local car manufacturer?
> pick up a magazine dedicated to companies announcing their products in particular domain.
Without ads, how would those magazines be monetized?
> Or these days, Google for a solution to a particular problem.
SEO = Marketing