Adding fields to users on social signup


I’d like to track referrals and the way to do this is to add fields to the user profile on signup. I was recently made aware that the package I created to do this does not work when a user signs up through social login (i.e. Facebook, or Google signup).

Does anyone know of a way to hook into this signup process?

I received one answer on SO that I’ll have to use if there aren’t any less hacky solutions. Here’s the SO answer: