The sale has ended.
Packtpub has been actively publishing books on computer programming and related subjects for some time. More recently they have also released several titles about data analysis with R. I have found in recent years several nice books in their catalogue, and this Christmas sale of their full catalogue of approximately 2500 eBooks at a flat price of € 4.80 / $ 5.00 for DMR free PDFs and other formats, and no limitations to repeated downloads is really a nice opportunity to get hold of some good books for little money. Here are some examples of books which I have found useful or good from this publisher:
You can get books at the discounted price through Packtpub offer
Caveat: I had written the post before I received an e-mail from Packt publishing offering to give me two free book PDFs if I wrote such a post.