Same thing is true of football cards here in Europe, to complete 1 sticker book, like for the forthcoming world cup someone calculated will cost something like £1500.
I can't remember the numbers, but there's 32 teams of 11 players (not including subs), there's 8 cards in a pack, of which there are typically 2-3 duplicates, so you need to buy multiples of the same team just to complete one team and then swap with friends at school to complete the others.
And that's the hook that gets ~~kids~~ parents buying, it's the element of peer pressure. My boy is not into football and isn't collecting the cards, he's currently a social outcast as a result. Fortunately, he has a strong character and isn't bothered by it, but peer pressure is the answer to your question IMO.
I can't remember the numbers, but there's 32 teams of 11 players (not including subs), there's 8 cards in a pack, of which there are typically 2-3 duplicates, so you need to buy multiples of the same team just to complete one team and then swap with friends at school to complete the others.
And that's the hook that gets ~~kids~~ parents buying, it's the element of peer pressure. My boy is not into football and isn't collecting the cards, he's currently a social outcast as a result. Fortunately, he has a strong character and isn't bothered by it, but peer pressure is the answer to your question IMO.
Edit: typos.