It's not possible to do a true move of existing keywords using the
AdWords API (or the AdWords web interface, or any other system that
I'm aware of). You can only delete existing keywords and create new
ones. It's possible to automate this process in a UI so that it
appears that a move is taking place, of course.
The article you linked to in turn links to this AdWords Editor Help
the last paragraph of which says "If you paste keywords in a new ad
group, the keywords' performance statistics, such as impressions and
clicks, will not be transferred to the new location." This is what you
would expect if a delete and create were taking place.
-Jeff Posnick, AdWords API Team
On May 29, 1:05 pm, "Peer Jakobsen (AdWords API Guru)"