Adam Martin remembers taking boxes of Panini stickers and their accompanying World Cup albums to a Formula 1 race in May, shortly after his collectibles shop had received a shipment and long before the tournament was to begin.

The idea was to give them to friends with kids. But what happened next surprised him.

“When I walked in with this box of cards,” Martin recalled, “hundreds of people of all creeds and cultures said something: ‘Where did you get those? How can I get some?’ Those Panini stickers are just that iconic collectible that goes beyond sports collectors.”

The stickers depicting players and teams in the World Cup have been around since 1970, when four Italian brothers paid $1,000 to procure the rights to produce the images. More than 50 years later, the stickers are available in packs all over the world, and fans young and old not only purchase them but also swap among themselves, helping each other fill their keepsake albums.

This year’s book is the largest ever, partly due to an enlarged 48-team tournament, with 980 distinct stickers. They’ve become such a hot commodity that many stores are sold out, and backorders may not ship until the tournament has crowned a champion.