From your description, it sounds as if with the way you're data is structured you just need to use the "Measure Names" and "Measure Values" special fields. I've attached an example using the Coffee chain sample data.
Right - I've been doing that. As with your report, which comes formatted as a stacked bar graph, my view doesn't "want" to be formatted by stacked bar graphs, and when I select a different graph type with your report, it won't allow me to select stacked bar graphs.
What are the absolute requirements for a stacked bar graph?
I presume you are using "Show Me" are you? It took me a while to figure out what you meant because I almost never use Show Me.
I think this may just be a case where you have to put the fields on the shelves and choose the mark type by hand, rather than relying on the suggestions from the Show Me feature.
Yes, through "Show Me". But you're right. Removing all but one of the items from my shelf resulted in a stacked bar graph. So, how about a stacked bar graph right next to other bars, grouped by the same book genre? So, The sum of all sales as a stacked bar, adjacent to, say, numbers of units moved, either stacked or not. The measurement axis would be absent and inherent in the bar itself (only on mouse-over would you see the numbers)? That way a single book-store has a stacked bar and a whatever else bar(s) together, without breaking the view apart.