I think the "supporting content" is pretty key. As a prospective consultant, few things are as powerful as 1) "Here is an example of me doing some awesome XYZ f

I think the "supporting content" is pretty key. As a prospective consultant, few things are as powerful as 1) "Here is an example of me doing some awesome XYZ for other people, proving I can deliver a mutually-beneficial artifact," and 2) "Here is an awesome proposal for XYZ, which I will deliver for you if it seems acceptable." Some links to e.g. case studies, articles, blog posts, etc could serve as both. That said, I wouldn't expect a high conversion rate. I would think the people doing the recruiting would lack the authority to change the gig from a job to a consultation. And if the manager him/herself is soliciting, they may be looking for a permanent addition to their team, instead of a one-time deliverable.