Other items of value include its billing relationship with 132 carriers, and a developer community with ties into emerging markets, where Microsoft is relatively weak.

FORBES: Nokia CEO-Paying To Be Microsoft's Future

True, when a newspaper or magazine reader drops his paper for a Kindle subscription, he enters a billing relationship with Amazon rather than the publisher. (Neither Amazon nor its partners will reveal how the revenue is split.) But for record labels, Apple was the only viable and legal route.

ECONOMIST: Electronic-book readers

Since all the parties to these contracts would like to tailor the contract terms to optimize their profits or minimize their costs, they have a tremendous need to customize the billing and compensation for each relationship.

FORBES: MetraTech Wants to Build a $1 Billion Payment Platform Business