Developers receive 80% of Samsung In-App Purchase revenues from November 1, 2013 to April 30, 2014. The previous profit distribution rate (including In-App Purchase profits) from the sales of applications was 70% for developers and 30% for Samsung. But to stimulate interest and promote development in the Samsung Apps ecosystem, Samsung introduced a temporary profit distribution rate to better benefit developers.
Sales of paid applications are not subject to this profit distribution rate, and this rate applies only to the sales profits of In-App items of applications using In-App Purchase 2.0. (If the application is distributed after November 1st, it takes 3 to 4 working days for the new profit distribution rate to be applied)
You can find more information about In-App Purchase 2.0 at the following URL.
Listen to SVP Curtis Sasaki talk about In-App Purchase at the SDC 2013 Keynote (Here: from 27:16 to 28:14)