That source says that that money is over the apps lifetime. So divide that by 4 (?) and its starting to become more limited. EDIT to include the quote (the low end of the scale starts to make things quite tight by my guestimating):

>>> TL;DR: Final estimate is somewhere between 0.15% to 0.60% of the iOS market, netting it somewhere between $875k to $2.3m for the duration of its existence (not yearly)<<<