You think 50 billion is a big number? It's certainly a bit bigger than some other numbers that spring to mind, such as 48 billion, and that in itself gives Apple something to celebrate. As is customary with these App Store milestones, whichever lucky jackanape triggered their download at just the right millisecond will receive a gift -- a $10,000 iTunes voucher, no less -- while 50 runners-up will get $500-worth of credit each.
But none of that is the really big
