When I started what became americanradiohistory.com it was a simple first step. I was often asked, professionally and among radio friends, about station owners, formats and such from the past. I had a few Broadcasting Yearbook issues and put them online. They got a few hundred views a week, as they had not been found by search engines and I did not have a clue about SEO.
But I got requests for more. I added more yearbooks. Then Broadcasting Magazine, and the page views increased. I got rather frequent emails saying, "they used to have that magazine at the library here, but they told me they had discarded it due to lack of interest."
As that happened nationally, my page views increased. I've had days of 30,000 to 60,000 page views, and average a half-million a month. That must mean that there are a lot of people who want the information and no longer have access to it.
I have had a number of offers from museums and universities to form a partnership. I'd only do it were the open access and free downloading to continue. For the moment, we have site curators and I have a succession plan.
Occasionally those items go to "friends of the library" groups that raise money selling on eBay. But usually it's the dumpster.