There's a South Park episode about collecting underpants for profit. The episode goes - okay it's a 3 step plan.
Step 1: Collect underpants Step 2: ????? Step 3: Proft!
So he's joking that these guys have figured out the step 2 finally, so the gnomes can profit from collecting underpants.
Huh, I've gone many, many years knowing the meme, but not until today did I know it came from South Park