Monster Strike continues to print money for maker Mixi (2121).

According to the latest financial report released by the company, the mega hit game pulled in a whopping US$378 million in sales between April 1st and June 30th.

In other words, Monster Strike made Mixi US$4.2 million per day in that time frame, and the game isn’t showing any signs of weakness.

Here is the corresponding chart from Mixi’s FY2015 Q1 report (“entertainment” is essentially the Monster Strike business):

These numbers translate to annualized sales of US$1.5 billion.

What is especially astonishing about the FY2015 Q1 figures is that:

close to 100% of sales should come from Japan alone (in fact, Mixi is currently in the process of closing Monster Strike in China where it already doesn’t accept new user registrations anymore)

Mixi operated with a 48.6% operating profit margin in the last quarter – and that includes all of its other businesses like ticket sales, photo sharing services, or its eponymous social network

Japan is home to GungHo Online Entertainment (3765), which operates its own hit Puzzle & Dragons with sales numbers in the same ball park

Mixi “just” spent around US$21 million in advertising (overall) in the same quarter – or US$230k per day

On an annualized basis, global companies like Supercell generated only slightly more sales last year while spending 4-5 times more per day on advertising: it pays to be the leader in a high-value, largely closed market.

Monster Strike is already available in English in North America – where Mixi plans a “large-scale” marketing campaign in Q2.