Choosing the Right API Strategy for Telcos [INFOGRAPHIC]
Learning from the successes of the Web, Telcos have moved their attention from internal to external information exchanges. Leveraging on APIs as the prime medium to an open ecosystem, operators are able to expose network assets as well as disseminate a wealth of useful subscriber information to external developer communities opening up a steady stream of secondary revenue from optimizing usage of its existing core assets.

Sources:
https://hbr.org/2015/01/the-strategic-value-of-apis
http://alanquayle.com/2014/08/myths-misconceptions-telco-apis/
http://money.howstuffworks.com/business-communications/how-to-leverage-an-api-for-conferencing2.htm
http://searchcloudapplications.techtarget.com/definition/API-management
http://www.slideshare.net/jaquayle/independent-review-of-telecom-apis
http://www.slideshare.net/ibmapimgmt/the-api-driven-business-model