Consider your math is based on 1 subscriber. Certainly their jaws would be wore out....then again, were they only talking to themselves on that line? LOL
Anyway,
If you conservatively figure 500k subscribers, those 2 Billion minutes would equate to 4000 billed per subscriber. Considering there many plans offered here in the States with 1000 minutes per month....these kids talk, talk, talk....about what..havn't a clue?
So, if using conservative #'s this 2B # may not be so far out?
Just my thoughts....