Thank you for the response Kevin. However, we are already a developer with commercial applications for product feeds and adword manipulation. We are trying to complete an application which aids our merchants/clients in Product Listing Ads - which we are not really having any difficulty with. When working manually (not through the api) we simply link our merchant account to our adwords account and then choose that account when setting up a PLA campaign - the question is "what is the best way to do this via the API instead of manually". Sorry for any confusion in my question -