I've just noticed I missed a minor milestone a couple of weeks ago: £1000 spent on Kindle books.
It's almost 8 years since I got my first Kindle, so that's really not a huge amount. A little over £10 a month, which is less than I spend on my train fare every single day.
On the other hand, I have only read just over half of that value, so there's about £460 that could have stayed in my pocket.
(My total for all other ebook vendors added together is roughly £175.)