I got an email from SugarSync a couple of months ago that since my account was inactive, unless I logged in, they were going to delete it. I couldn't remember if I had uploaded anything to it, so I went ahead and logged in.
I don't plan to upgrade and I guess I should at least go in and delete my files. (If I remember; I can't access cloud storage from work; they are all blocked by the firewall. I signed up for SugarSync because it wasn't blocked, but that didn't last long.)
I would like to have a second cloud service (besides Dropbox) where I can copy over my Calibre library. I just recently discovered how convenient it is to have my books there, but I am filling my Dropbox with photos and would like to store my books somewhere else. I have been considering using SugarSync or signing up for Copy, but it seems like there is a new service popping up every month and I haven't taken the time to investigate any.