I think you left out a crucial part. How did you develop the skill to spot a fake? The encyclopedic domain knowledge that you possess is the anchor of your business and the value you being to the table. How did you gain that knowledge?
Honestly I just 'hamstered' all the material I could on the most popular items.
In the beginning, in those first 10 guides I mention in the article, I just curated all the splintered bits of info* from the internet into one mega-guide, and added what I found after analysing fakes
* bits of info from as little as a forum thread comment, lost on page 48, to a full-blown attmept at a guide that, to me, wasn't exhaustive enough
In time, it refined to partly what I did in the beginning, and partly our own research which got better with exercise
Package all that info in a free, properly formatted guide (with some imperfect English, I admit, as we're not natives), and that gives us the traffic figures I screenshot'd
I do believe in moats, and I'm trying my best to see what moats I can build on top of what we have to 'protect' the business