The other play to throw in the discussion is Jerusalem, which ran significantly less time but also extended through the summer. (At that time, Rylance was not a known quantity outside of the theatre.) I think there are a lot of factors, including the length of the show, the subject matter, summertime (when it is still daylight when you have to head to the theatre, when kids are in tow, when it is hot, when there are cool things to do outdoors in the evening, etc.) I agree about a tour because it will skim off the interested audience in what I assume will be relatively short stops. I'd be skeptical of a lot of regional productions.