In its ongoing mission to make learning great again, Kahoot! today hit a number of stats few companies can brag about: The company celebrates 40 million monthly active users and a total of 1 billion players moving through its platform over the past four years.

“We’re over the moon at Kahoot! with the sheer passion and drive from the community of educators and students who believe in our mission of making learning more awesome and fun,” said Erik Harrell, the company’s CEO. “Our highest purpose is to help learners realize their deepest potential, both inside and outside of classrooms, and to create the most relevant global learning brand for today’s learners.”

The company raised another $10 million in September last year to drive growth. It is announcing it’s investing heavily in development of additional game formats, mobile apps and partnership features for brands and publishers.

“We’ve seen 60% growth since this time last year,” says Harrell, revealing that the vast majority of its players (67 percent) are based in the U.S., with strong growth among teachers. “We have more than 2 million K-12 teachers in the U.S. who’ve signed up for our service. More than a third of all U.S. students at the K-12 level use our product on a monthly basis.”

Holy market penetration, Batman.