The digital-wallet business is rough — just ask Google

The other significant barrier that Google Wallet faces is a lack of cooperation from the carriers. While a decent amount of Android, Blackberry and Windows Phones have NFC enabled in their hardware, only Sprint allows Google Wallet on devices. Having to battle with other carriers, on top of other wallet companies and Apple, with its own forays into Passbook, will further stretch Google Wallet as it struggles to find a steady audience that has access to the product.

Like many of its now-shuttered projects, Google Wallet may have entered the mobile-payments market too early and too strong to make a real play at domination. Forrester Research estimates the space will hit $90 billion by 2017, but that’s a long time to wait and see if a major investment will turn around — even, perhaps, for Google.