We initially started out with tiered pricing based on storage. However, based on usage, we actually found that people rarely hit their storage caps. A better barometer for us is the number of people working together, which we approximate with projects. In that regard, our pricing plans are similar to Github's. Public projects are free and unlimited. Private projects are paid.
I'm not understanding how a version is identified, though. Is a version stored on the server every time the file is saved?
I don't see anything about locking. How do you prevent two people from working on the same unmergeable file at the same time?
Speaking of merging, there is no mention of merging of text files. Is that not supported?
*Sketch files are actually folders with data, previews, etc. The act of opening the file actually modifies things like the thumbnail.
Sketch just officially launched 3.1 two days ago which creates files that are actually single files. We can still support version control for these files, but we are working on fixing the preview generation for the new Sketch format.
[1]: http://helpx.adobe.com/photoshop/using/file-formats.html#lar...