"As the largest retail mobile payment platform in the U.S., we're excited and proud to accept payments with Square, " said Howard Schultz, Starbucks chairman, president and ceo.

ENGADGET: Starbucks switches to Square for payments, invests $25 million and will support Pay with Square

This represents 19% of global e-Commerce and just 2% of global commerce, leaving generous room for upside. eBay itself is becoming a formidable third-party reseller or marketplace ala Amazon in its own right. eBay has moved beyond a person-to-person auction site to become a formidable marketplace and mobile payment platform. eBay has appreciated from its IPO over 7, 000%.

FORBES: Importance of Being a Platform (Apple, LinkedIn, Amazon, eBay, Google, Facebook)

American Express and Verizon Wireless today announced they will integrate Serve, a next-generation digital payment and commerce platform, on many Verizon mobile phones and tablets.

ENGADGET: Verizon Wireless to tie American Express' Serve into mobile numbers, keep your credit card holstered

Google Wallet is the first mobile payments service to really show promise in adding capabilities like the above on top of a base payment platform by bringing their ecosystem of local services like Google Places and Offers into the fold.

FORBES: The Value Of Mobile Payments Is Beyond Transactions

Businesses are being launched on the mobile platform to provide a wide range of services from medical advice and diagnosis, to pharmaceutical authentication, to payment and finance systems.

FORBES: Two Technologies Propelling India Forward