Seth was right, in terms of metaphor, in saying that hard disk space would be free. I heard the somewhat less popular Bill Gates say something similar in the late 1980s: when you think about the future, assume that storage, memory, and bandwidth are free.

None of that's quite true, of course; it's only the relative cost that's fallen. Some people with smartphones may not be able to accurately state the total cash outlay over two years (often close to US $3,000) for hardware, voice and data services.

Clearly cost is only one variable in the equation, but it's not one to ignore.