Fees can be extracted in many ways: While Android is open source, the Google app...

AdieuToLogic on July 29, 2015 | parent | context | favorite | on: Microsoft’s new small print – how your personal da...

Fees can be extracted in many ways:

  While Android is open source, the Google
  applications, like the Play Store, Gmail,
  Google Maps, Google Play Services, and others
  must be licensed. This licensing agreement is
  called the "Mobile Application Distribution
  Agreement" (MADA) and comes with tons of
  restrictions.[1]

This is only one example and the monetary considerations are unknown.

1 - http://arstechnica.com/gadgets/2014/02/new-android-oem-licen...

icebraining on July 29, 2015 [–]

The link I posted above explicitly says they don't charge for those applications and services.