QuoteOnce they've purchased something through Google Checkout, consumers can track their orders through the system, which will be live starting Thursday at Checkout.google.com. Merchants using the system will be charged a processing fee of 20 cents per transaction, plus 2.2 percent of the relevant purchase price. Customers who pay for search-related keyword ads through Google AdWords will be able to process, free of charge, transactions that add up to 10 times the dollar amount of their AdWords spending, Kamangar said. Beyond that, they pay the 20 cents plus 2.2 percent. Kamangar said the regular transaction fees are less than those charged by credit card companies, which can be about 1 percent higher.