Streamlining Lead Capture: Managing Returning Survey Responses

SURVEY Q: Let me give you an example: Say I have a landing page with a freebie to capture new “leads”. Candidate wants to download the freebie and enter their email. A survey pops up with questions (first name, last name, linkedin URL, and “what content are you interested in?” if they return for a different freebie later, how do I make sure they don’t have to fill out those same details again?