I am probably the perfect target customer for this: I love and depend on Dropbox for a lot of things since I'm on the move all the time, but I do not trust them with my sensitive data (and I include in this category all of my business data - invoices, et. al). I already have a cheap, mass-storage server colo'd for offsite backups, so being able to run my own copy on my own hardware is a godsend for me.