St. Jacob's oil for veterinary purposes : in yellow wrappers : superior to all other liniments and embrocations / The Charles A. Vogeler Co.
The pattern
This still is filed under Keepable trade card.
Define
A small card people keep (pretty, useful, or collectible) that carries the brand after the encounter.
Mechanism
Retention object. The gift is the media. Recall is paid for by usefulness or delight, not by repetition.
Verdict
We can put a physical or digital keepable in someone's pocket and they will not throw it away.
Why it works
It solves the problem of cross-contamination/confusion between human and animal medicine by explicitly calling out the 'YELLOW WRAPPERS ONLY' branding.
Steal this when
You are expanding a successful human product into the veterinary market and need to clearly distinguish the packaging to prevent confusion.