Which is fantastic!Let's not overlook that you've also passed the 500 backer mark. You've officially sold more copies of your book than Rokka no Yuusha's Blu Ray sales.
But also Blue Ray was a short lived version of CDs going into a time of Streaming. So it's not surprising that there's not a ton of sales for it, these days.
Not that I'm discounting the success! This is -massively- more than I anticipated selling. And beyond even that on the actual revenue...