A natural blab barrier?
Analysts predict that we can probably not spend more than 35 nonwork hours a month on the phone according to this Wall Street Jouranl story (subscription required):
...we're rapidly approaching what the phone companies quietly dread: our natural blab barrier. In other words, we have just about reached the point where we have no more words left to impart.
It's the same kind of feeling you get when you circle an elaborate buffet table. You first think you can eat all that roast beef you took, but inevitably you leave a slab or two on your plate. Market research firm J.D. Power, for instance, reports that the average cellphone user talks 541 minutes per month, less than 40% of the 1,359 minutes available on the average plan. (That usage would roughly average 135 minutes a week, or just under 18 minutes a day, although in real life, usage changes throughout a week.)