LEGO sells roughly 220 million sets per year, with LEGO Harry Potter being one of its most popular themes, possibly comprising about 25% of all sets sold. The LEGO Group's annual revenue is approximately $9.6 billion, with a profit margin of about 28%. Assuming JK Rowling receives 5% of the profit from Harry Potter-themed LEGO sales, the calculations would suggest she earns around $33.6 million USD per year from this, which equates to about $92,054.00 per day.