This a light add-on for Google AdWords dynamic remarketing tag.
Dynamic remarketing lets you reach your past site visitors with ads that show the specific products people viewed on your site. Once you've set up your dynamic remarketing campaign, you'll need to add the dynamic remarketing tag, including custom parameters, to your site so your lists can start working.
More on: https://support.google.com/adwords/answer/3103357?hl=en
The support thread is at: http://forums.oscommerce.com/topic/393619-addon-adwords-dynamic-remarketing-tag/