Progressive Profiling - For Specific form or website?

I'm wondering if progressive profiling is based on a lead returning to one specific form, or when a lead returns to our site through a different landing page and different form. To clarify, I'd like to use progressive profiling for a new webinar form, so someone will not be returning to this form. However, I'd like to pull their data if they're already in our database. Would progressive profiling work by pulling in information the lead has entered on a different previous form?