Nice idea , but it could easily be manipulated.
How about authors can flag certain item comments as their favourites – and these appear on the profile page, or higher up on the item page.
1. someone submits a testimonial about you on your profile, cause he’s a satisfied buyer.
2. if you like it, you could switch it from private to public
3. you could display maybe 3 of them on the sidebar of your profile, a section called Testimonials
I think that would be a loooot more useful than to know who purchased your files… the buyer decides to tell you what he did and that he’s satisfied with it
that would give you more potential buyers…what you think?