Picking the best platform for your affiliate program is a vital part of running a successful affiliate marketing campaign.
There are now endless platforms including, blogs, website, Instagram & Facebook, and much more. Anywhere you can build a following you can run affiliate programs. If you already have a good following on the platform I would suggest going with them.
If you are starting from scratch I would match the program demographic with the platform’s demographic. i.e If you are promoting a fashion affiliate program, where the target market is females between 18-25, Instagram maybe a good place to start.
At the end of the day good content on any platform will attract a following, so that is most important.