The LeapPad, which is pitched as a learning tablet for four- to nine-year-olds, was voted Toy of the Year by retailers last week at the British Toy and Hobby Association's Toy Fair.
Sales were driven by strong word-of-mouth marketing and social media sites, without TV advertising, according to Chris Spalding, managing director and senior vice-president EMEA and Asia at Leapfrog.
He attributed the product's success partly to the uptake of the mobile and tablet devices such as the iPad and iPhone among parents, which meant tots catching the touchscreen bug.
Spalding said: "If [children] see their parents with their BlackBerry or their iPad or their iPhone, they want to emulate what their parents are doing.
"In these days of social media and the internet, that's a very quick way to get the message out."
He added: "We were selling them quicker than we could make them."
Hornby Hobbies, which launched its first TV ad in three years for Christmas last year, picked up three awards (Best Hobby and Model, Best Olympics Toy and Best Pocket Money Toy) at this year's fair.
Nat Southworth, sales and marketing director, Hornby Hobbies said: "Our products span all generations – it's a fantastic strength of ours.
"Originally, they were made as toys, and then the kids grew up and they still wanted them. They then changed their name to be called collectables."
To see the full interview with Spalding and Southworth, watch the video above.