The change of heart—covered quite well in this Investor's Business Daily story—is part of an overall cost-cutting program at Google. "They are cutting back on things like their free cafeteria hours, subsidies of their on-site daycare, so trimming subsidies to their merchant partners is no doubt part of that belt tightening too," Forrester Research Analyst Sucharita Mulpuru was quoted as saying.
For years, Google has given its Google Checkout service to retailers for free, as long as they bought ads on Google. Alas, no more. Explained one Google manager: "Why have it as a loss leader if it's doing OK? We saw very healthy results after we decided to charge for the service."