Google Base is soon to allow merchants to sell through Google's own payment system, as well as allowing buyers to use the Google Accounts system to make purchases. A quick look doesn't show any of this live yet, but I'm sure examples will come soon. There is more information from Google here plus a note on how this fits into their overall payment system plans here. Want to sell on Google Base through its own system? Use this form to sign-up.
Optimising Digital Marketing Campaigns with Search, Social and Analytics
At SES London (9-11 Feb) you'll get an overview of the latest tools, tips, and tactics in Paid, Owned, Earned, Integrated Media and Business Intelligence to streamline your marketing campaigns in 2015. Register by 31 October to take advantage of Early Bird Rates.