[ndriscoll]

They publish contact information for vendors? They reach out to vendors through their published sales channels? Go to industry trade events or follow industry periodicals where that's the purpose?

They'd highlight new products because they believe they're good.

The solution to your last problem is to make exclusive dealing contracts always illegal and actually enforce antitrust law.

[sanswork]

All your solutions are forms of advertising.

[ndriscoll]

Contacting a sales department at their provided address for that purpose is responding to a request for you to do so. This is nothing at all like taking money to propagandize people.

Putting a product at a prominent part of your store because you think it's a good purchase for customers is also completely different from accepting money from a manufacturer to place it prominently.

Going to an event where everyone specifically went to meet and exchange information about what people in their industry are doing is also again entirely unlike paid promotion.

[sanswork]

Right direct sales is not advertising. The rest still is.

You're missing a step though. There is no consumer pull for new products so there is no reason for stores to bother with them even if the owner thinks it's a great idea. The demand isn't there

[ndriscoll]

They have a similar reason that the product developer had to make it: they have customer empathy, can identify a good product that satisfies a need when they see it, and know how to explain it to customers.