I agree with you, Alan. That's how most people do it.
I've found through a few small retail sites and a couple of information sites, that publishing useful or interesting content can be enough that other people will share it for you. There are still niches out there where one or two people, working as a team, can produce, in two or three years, more content and better content than all of the competitors in the niche combined. Once you have that, then some of the people who find your site and see the depth of content, will share it for you. And, there are some topics where people will search deeply for the right information.
If you have a hardware store or a toy store or a jewelry store, you don't have to attack the entire industry. Instead, focus on a very small niche of products that are typically not represented well in local stores, and that do not have an online champion.
The niche must be chosen carefully.
I don't have any interest in social media, or making personal connections, or in soliciting others. But, I do have an interest in learning the deep technical details of things and enjoy writing about them. Through that, I provide the community service similar to what you provide. Then a steady stream of visitor questions coming in and being answered, first by email and then published to the content library that provides a service to a consumer community - these are coming from people who may have first purchased at amazon or or some other vendor who places 100% of their effort in making the sale but places zero effort in helping the customer after the sale.
These people are out searching deeply. They feel like they have been abandoned. This is today's internet - Walmart, Amazon, Jet, and others are all focused on the aggressive price competition. Service after the sale and deep information for the consumer has been abandoned at the very time when you think it should be abundant. Nobody wants to write it. How many times have you purchased something and could not understand directions that were written on another continent and then translated into English by someone who knows the language poorly.
That leads to a problem in that you become the default service department for amazon! They don't do it. But if you step into that role you quickly obtain a knowledge of what information people need and when you answer an email, you also place another brick in your relevant content library. So, although I am not making any direct outreach at all to advocate a brand, engaging a community, or soliciting on my own behalf in any way, the questions keep coming in, the content mass continues to grow, and it attracts more and more traffic year over year.
Most business owners are not going to do this because they don't like to write content and they don't have a situation that allows them to invest a lot of time now and not be paid back until years down the road. No SEO will do this because the upfront labor is very high and the return isn't fast enough to satisfy a client. These opportunities are perfect for the person who enjoys working from the cloister.