Business has been so brisk at the world's most profitable toymaker that Lego did something unusual last year: It began looking for ways to discourage customers from buying its products.

The Danish company scaled back its advertising efforts amid a 25 per cent rise in annual sales, according to Reuters. It simply couldn't make enough toys to satiate demand in North America, and needed a break while it boosted capacity at its factories and increased its workforce by nearly a quarter.

"We feel we need to invest, to build some breathing space," Lego's finance chief John Goodwin explained.

Lego, a family-owned company founded in Denmark in 1932, has enjoyed booming growth for decades. The company has released thousands of sets of its eponymous blocks, forging licensing deals with popular brands including Star Wars, Angry Birds and Disney Princesses. It has also taken on iconic architecture: A 2989-piece model of the Sydney Opera house is for sale on Lego's website for $399.99, while a 561-piece White House set sells for $89.99. A replica of the Ghostbusters firehouse, meanwhile, is listed for $499.99.