Optimal unlocking mechanism for booster cards is unclear
When creating booster cards, there are a few different mechanisms for unlocking the cards that one can imagine:
- time-based unlocking: 3 months after you read the initial essay, you go to collect booster cards, or the booster cards get added to your deck in one or more installments.
- content-based unlocking: when you complete chapter 5 in a book, you go to a special place to collect the booster cards for chapter 2 (or maybe they just get added to your deck automatically).
- review-based unlocking: every time you go for a review, a small amount of booster cards get mixed in with material you've already seen.
actually there's two axes here: how the unlocking is paced, and whether you go out of your way to collect the cards (possibly reading some review material or "booster material" as well) or whether they get magically added to your deck.