I want to add a "Where did you hear about us?" checkbox list to user profiles. There will be 6 radio buttons and an "Other" textfield.
There's no need for a taxonomy vocabulary, which was my first thought. I also thought about using Webform, but that feels like overkill and I think I'd have to do more work to link the form to the user.
Really, I just want to view the user profile and say "Oh look, they found out about us from twitter ...". So what are good techniques/approaches to implement this?