Making the right decision might have a long term impact on how effective your application can use and interact with the data that is retrieved back and sometimes justify how much you can earn back from your hard work put into the application development process.
Both REST and SOAP are popular standards for interacting with web services. And in case you didn’t know, in Amazon’s Web Services, 85% of developers chooses to work with REST instead of SOAP when they were given a choice (which in fact, there is).
However, don’t be disappointed if you’re using SOAP. Not all of the affiliate networks today have the option of either REST or SOAP. CJ is one of them and they currently only support SOAP.