Nobody knows why Swedish tradition demands seven different kinds of home made cookies if it's to be considered a proper cookie platter (usually accompanying coffee). It's a custom that suddenly gained popularity in the late 1800's, and its origin remains a mystery to this day.
What we do know is that food and retail company ICA dates back to 1917. In 1945 one of its subdivisions held a competition for cookie recipies yielding more than 8000 entries. The best recipes were compiled into a collection that quickly became a household staple in Sweden. By 2005 the 84 continually revised editions had sold 3,4 million copies over the years. An edition in English was released in 2008 and is the ultimate christmas gift for any baker with a Scandinavian heritage or interest.