A core challenge for the Mnemonic medium is that Regular spaced repetition memory practice is an onerous habit to adopt. Happily, The mnemonic medium scaffolds prompt-writing through author-provided prompts. Author-provided prompts lower the cost (no need to write prompts) and deliver more value (they’re often high-quality). But regular memory practice still poses a significant fixed overhead. It wouldn’t make sense to start a new habit for the sake of remembering just ten prompts. A reader’s prompt collection must have higher value than the cost of practice.
To put it another way: the prompts presented in the first few weeks of practice play an outsized role in a user’s experience. Quantum Country has about 200 prompts, which is enough scope on its own to justify a memory practice (for someone who’s committed to learning that topic). By contrast, a single article with 10–20 prompts probably can’t deliver enough value to justify starting a practice habit… but if a reader already had an active habit, it would sweeten the deal. And if there were dozens of smaller mnemonic articles which interested the reader, that would probably be fine, too.
A reader’s introduction to the medium should cover material that’s quite important to them, and with enough depth to be worth adopting a new habit. So widespread adoption of the mnemonic medium depends on focal points like Quantum Country, which are significant enough to act as springboards for lighter-weight use cases.
Relatedly: Spaced repetition review sessions can become boring and detached without a steady stream of new prompts. So there must be not only some substantial initial content (like a textbook), but also a steady stream of follow-on material for people to use. Or else they must be bootstrapped into writing their own prompts.
Devon points out (2020-04-20) that she’d actually expect it to be easier to onboard with smaller pieces of content, since then the review sessions would be quite small. I’m skeptical that she would stick with a review practice of only, say, 20 prompts, but this approach might work well if there were many articles available—for instance, if Marginal Revolution were annotated in this way.