It would appear as though Google's decision - so far - to concentrate its Wallet on the US market is part of the growth problem. The strength of Android is in its worldwide percentage, rather than fighting Apple where it has the strongest position with the 'big spenders'. The ability of Google to service the less wealthy but far bigger international market is where the Wallet can score heavily, not least as the external US market is more concentrated on mobile payments. It is also where transaction processing can add income, based on currency conversion fees and the facility to enable US merchants sell products to a diverse market. While the processing fees are less important than the data, they do make for a specific business case for the wallet in its own right.