9x12 album sizes

I have seen lots of people (mostly in the Ali Edwards community) who have being going crazy over the 9" x 12" scrapbook size and many of them have switched from 12x12 Project life to this. It's not something I have seen over here though? I guess it just hasn't caught on as much as it has in the states?
I was intrigued as it still follows the pocket page format :) Even a quick search of this site has shown it was a thing many years ago (funnily enough I don't remember seeing it myself!) but again I guess because it didn't catch on then stockists stopped selling it.

Studio Calico have recently reintroduced the 9x12 album. I also know quite a few UK scrapbookers who have switched to A4 which is similar so they can use normal office lever arch files rather than costly scrapbook albums.