At least since the appearance of data sets that lent themselves towards such visualization. For example, how better to compare the growth of various platforms, from TRS-80 days to the iPad while the entire industry grows exponentially?
http://www.asymco.com/2012/01/17/the-rise-and-fall-of-person...
Edit: But I guess that's really market magnitude over time, not quite what you asked.
At least since the appearance of data sets that lent themselves towards such visualization. For example, how better to compare the growth of various platforms, from TRS-80 days to the iPad while the entire industry grows exponentially?
http://www.asymco.com/2012/01/17/the-rise-and-fall-of-person...
Edit: But I guess that's really market magnitude over time, not quite what you asked.