Wow, I'm surprised you cannot share stacks and that Evernote doesn't then have a subnotebook option. I just spent a lot of time creating notebooks, dividing notes into them neatly, only to realize I can't share the stack. This is extremely frustrating, because I just wrecked a project I've been working on for my department at work and will have to spend a lot of time reverting. The use of tags seems like a flimsy workaround for something that would seem pretty obvious. I just purchased the premium version this week too for the advanced sharing options. Oh well..... I work in Customer Service and hate seeing negative feedback in feature requests on our forum, so I feel bad in writing this. However, this missing feature took the wind out of the sails of a great product. Without Evernote, I couldn't be as efficient as I am at my job and wanted to make sure my whole dept had this efficiency tool in their arsenal. Guess I'll have to redo my work and explain to everyone how to use this.
