It appears there is lots of confusion here, so I'll attempt to clarify things...
Dropbox and similar services are for managing FILES. That's it. You copy a file to Dropbox and you copy it back. End of story. The single "file" used by Realm Works is the database. For many users, that file is 500MB in size and sometimes much larger, depending entirely on how much material you've put into your assorted realms. Over time, it's only going to get bigger as you continue to evolve your world.
If you want to copy that specific file back and forth, you will run into problems, but you you CAN very simply move an equivalent file to and from Dropbox. Simply perform a backup on Computer1, copy the backup file to Dropbox, switch to Computer2, copy the file back from Dropbox, and restore from the backup file on Computer2. The process works equally well in the opposite direction. Setup the backup file to be "synced" by Dropbox and you can make this method work TODAY.
But all that does is copy ONE HUGE FILE back and forth. I'm guessing you probably want all the smarts that are being performed between the Realm Works server and the program on your desktop. If you only change one small thing, the intelligent syncing of Realm Works only transmits that one thing. If you change snippets on a topic that create and drop links to other content, Realm Works is smart enough to identify exactly what was changed, created, and deleted so that it only transmits those specific things.
Let's use an analogy that will probably be more familiar to many readers. Imagine you have a single word processing document that's 500MB in size. It contains everything for your entire campaign in the one document. If you add a few sentences on page 276 and revise a few sentences on page 423, the Dropbox solution requires you to copy the entire file. What would be vastly better is to only send the small changes up to Dropbox. Alas, that's not how Dropbox works, since it only operates on complete files. However, that IS how the Realm Works server works, syncing only the small bits that have actually changed.
Now let's look at the implications of Player Edition. Our assumption is that you don't want to just give your players everything and trust them not to peek at things they're not supposed to know. With Dropbox, your only option is to give your players everything - the entire database contents. Alternately, you could manually edit down the file that you give them, but then you have to manually do that every time, which doesn't work so well. What the Realm Works server does is identify exactly the information that you have revealed and send that information down to the players. If you reveal different information to different players (something that we've got designed in but haven't fully added yet), then the Realm Works server will properly determine exactly what information you've revealed to the particular player who's syncing down your realm. Only that subset of information is sent down to the player, as it should.
There are other benefits of the Realm Works cloud service that I could go into, but those two are the most fundamental and glaring distinctions from (comparatively) simplistic file storage services like Dropbox.
The syncing logic going on within Realm Works is incredibly complex. And it provides a great deal of power and benefit to those GMs who want those capabilities. If all you want is to backup of your entire database as a single file, then you can utilize Dropbox today (as outlined above) and have no need for the Realm Works cloud services. If you actually do want those capabilities, though, there is no way to provide them through Dropbox (and never will). You can't make a very simple, file-based service like Dropbox do incredibly complex logic like Realm Works. That is why we've developed the Realm Works cloud service and did not simply leverage services like Dropbox in the first place.
To recap: If all you want is basic file transfer and don't mind always syncing your entire database every time you make a small change, the Dropbox solution is viable today through the backup and restore functionality already provided. If you want intelligent syncing of only the small bits that have changed, or if you want to provide your content to players while restricting them to only the pieces you've revealed, then the Realm Works cloud service is the only way to accomplish that.
Hope this helps!!
