I hate it, they translate a book and decide that they want to sell it twice so they split it into two. They did it with every book of A Song of Ice and Fire and yesterday I’ve discovered they also did it with To Sleep in a Sea of Stars. I hate paying twice for one book.
A lot of books get split in English as well simply because they start hitting the limit of what print publication can do.
Most famous is probably the Lord of the Rings, split into 3 books, and Clive Barker’s Imagica, split into two.