Worth mentioning "Tangled Web" is probably the best overview of security issues that emerge from browsers and the HTML architecture. http://nostarch.com/tangledweb
I'm very unlikely to ever read this type of book again after I finish it, so needing it on a non-Kindle format if I were to ever switch to another e-reader is not that important. And unless there's a lucrative, legal resale market for e-books that I'm unaware of, there is really no point in even keeping the file around once I'm done reading the book.
It immensely benefited me -- a web developer familiar with the craft but lacking depth. It could be a difficult introduction to read cover to cover! By all means get it if you plan a deep relationship with web programming.