Hi Mark,
Zemanta can act as a great term extraction tools. We have many users
using it just for that.
API returns response in multiple parts. I think you should just look at
"keywords" part of response and you'll get what you are looking for!
What you are describing is "articles" part of response, just ignore that
if you don't need it.
Also attractive are "normalized" entities returned by "markup"."links"
part of the response. Some people prefer them over keywords since they
can be relied upon to mean some specific "thing" denoted by a unique URL
(wikipedia, freebase, imdb, ...)
Anyway, just take a look at "keywords" part of response and you will
find what you are looking for :)
thanks for giving us a try! Report on how it will go :)
bye
andraz