This makes me think that Square may be a "leapfrog" innovation. The best example of leapfrogging is cell phones and landlines. In the US, you might have briefly had people saying things like "cell phones will never replace landlines because there are sometimes you reallly need reception." In developing countries, no one bothered to ever wire landlines.

Here's the only article I could find in a ~1 minute search that explains in more detail the concept: http://www.article13.com/A13_ContentList.asp?strAction=GetPu...