During the later stages of Joshua Robinson and Jonathon Clegg’s book ‘The Club - How the English Premier League Became the Richest, Most Disruptive Force in Sports the authors discuss the growing importance of pre-season tours. The big six now travel to the United States, Dubai, Indonesia, Japan, South Africa and Australia to showcase their brand. These trips are typically outside of Europe and involve tours of 2 to 3 matches or some sort of pre-season tournament such as the International Champions Cup.
Attendance data is available for all of the Big 6 (non-European) preseason friendlies for six recent seasons. I take account of when the big six play each other abroad outside of Europe.
Prior to the 2011 season a combined average attendance for the Big 6 pre-season tour was circa 250,000. This grew to circa 315,00 in 2013 and peaked in 2017-18 at approximately 340,000. Since then it has dropped back down to about 300,000 for the start of this season.
While there appears to be a minimal amount of growth at an aggregate level, this may however have been down to specific countries visited or stadium capacities.