Interestingly, all German language e-books have been DRM free for a couple of years now. I have no idea how that happened, but at one point, all major publishers have pivoted from mandatory DRM to DRM-free (but watermarked) ePubs.
The notable exception is Amazon: Kindle books are almost always DRMed from the same publishers.
I really love watermarking as a solution for DRM-Free media!
Watermarks can of course be stripped, but so can DRM--the goal is just to add an extra barrier, which watermarks do without inconveniencing legitimate customers. I actually kind of feel it adds value--it gives my purchase an authenticity a pirated copy wouldn't have.
The notable exception is Amazon: Kindle books are almost always DRMed from the same publishers.