The raw says "トレカというカードゲーム", aka "a card game called toreka"(i.e. trade/ing card/s) the entire chapter except at the end where they specifically say "クロスワールドのパック" (crossworld pack). Why the author did it like this I have no clue...
I want to throw my two cents,
He probably meant "toreka (tra/ding ca/rd) kind of card game" [is what's in demand].
The Japanese has tendency to shorten words whenever, like BuruAka (Blue Archive), Dorakue (Dragon Quest). Just like us WuWa
Since there are card games that don't need to be traded, like Uno or Tanto Cuore, they're one off purchase and wouldn't have demand as aggressive as he has now.
As for specifically saying "Crossworlds" at latter part, he is saying that that's the series that hot now. Wouldn't want to make the mistake stocking football cards then.
Personally I feel most of these are self explanatory but that's probably me who need to touch grass. As trade-off I don't know much about car models on the road or fantasy football as much a man should 😂