They're not selling either. They are selling ease-of-use. Filesharing between multiple PC's you owned along with potentially PC's of colleagues was always dif

They're not selling either. They are selling ease-of-use. Filesharing between multiple PC's you owned along with potentially PC's of colleagues was always difficult and cumbersome. Dropbox pioneered an easy way to make file sharing among machines as simple as dragging files to a pre-defined location on your PC. And even this concept wasn't entirely new, Microsoft's "Briefcase" in Windows95 was basically an early version of this. Dropbox's success is all about the simple execution of a task that impacts millions of PC owners, and removing the difficulty of performing that task. Will filesharing make Dropbox the next Apple or Google? Doubtful. BUT, there are still several pain-in-the-ass little nuances about the multi-device world. IMO, they might look next to the overall interaction and data management among a household of PC/Tablet/Laptop/Smartphone users. One example: I have a set of contacts on my laptop. Call it "Everyone I know", My wife has a similar set of contacts on her PC. Some of these contacts are duplicates (family members), others are unique to each of us (personal friends or business associates). On each of our phones we have a subset of these contacts. I'm not a fan of having an over-filled phone contact list, I want to keep it to the most commonly-contacted people. My iPad has a completely separate contact list that is all disorganized. I'd like an easy way to manage a contact pool among multiple users and devices much like Dropbox manages files. I'd like to be able to edit or update certain info in my company address book, and sync certain contacts to certain devices. Dropbox has a huge opportunity just in making all sorts of information appear and share in just the locations we want it to be, among many other things.