Brochure for a potential buyer - American (10)
I believe the answer is:
prospectus
'brochure' is the definition.
(I've seen this before)
'potential buyer american' is the wordplay.
'potential buyer' becomes 'prospect' (I've seen this in another clue).
'american' becomes 'US' (United States).
'prospect'+'us'='PROSPECTUS'
'for a' is the link.
(Other definitions for prospectus that I've seen before include "Brochure giving details of college courses etc" , "Booklet of what's on offer" , "Promotional booklet" , "Outline plan for approval" , "Advertising booklet for school or university" .)