Google has announced that Google Product Search / Google Shopping will no longer be a free program beginning Fall 2012. Details of this major announcement can be found here:
Our blog post:
We encourage all of our merchants begin the transition as soon as possible. Google offers incentives to merchants already using Product Listings Ads and to those new to the program. Details of the incentives are in the Google blog post linked above.
If you have any initial questions, please file a support ticket through your SingleFeed account or email us at email@example.com.
We will be posting additional information on the support portal as it comes available.