This isn't a free book, but I know a fair number of people on this forum use Dropbox to help manage some of their e-book files, so I thought I'd post this here...
Yesterday, I put an SD card, which had some pictures on it, in my computer. I was surprised when a little window popped up from Dropbox, saying I could get free space for using the Camera Upload feature to upload my pictures to my Dropbox. I was so surprised, in fact, that I hit "close" as I do for almost all pop-ups
. As it was closing, I realized I might actually WANT to read that one
. So, I ejected my SD card, and put it back in again, and the same pop-up window appeared. I went ahead and let it do the automatic upload (even though I hadn't been planning to do this), and sure enough, 500MB of additional space appeared in my Dropbox.
So then I went hunting for info, and found out that this is a Dropbox promotion for their new Camera Upload feature, which can give you up to 3 GB of additional space, in 500 MB chunks, if you use "autoplay" on your PC and the Dropbox Camera Uploader to upload at least 2.5 GB of pictures. You can also do it from your camera, or other device. It appears the added space is permanent, so presumably you can delete the pictures from your Dropbox after you get the space, and upload books instead
Details, including instructions, are here, in a FAQ from Dropbox:
https://www.dropbox.com/help/287
It does appear (although I'm having a bit of trouble figuring out for sure) that the Camera Upload folder is public, just like the Photos folder, so you may want to be careful what you upload...
Also, not sure how long this will last...