Over at Marketing Pilgrim, Jeremy Luebke found that Google AdWords is testing a larger and more branded Google Checkout button in AdWords results which appear above the fold.
Google has been running their shopping cart icons for months in AdWords results for businesses which feature Google Checkout as a payment option.
However, users may not be responding to the carts and click thru rates may not be improving for Google Checkout merchants as much as Google anticipated.
Yahoo has also introduced their own labeling of Yahoo Advertisers who are Paypal merchants in their Yahoo Search Marketing ads using similar carts.
Perhaps Google is trying to differentiate their results from Yahoo Paypal results, but my best guess is that Google Checkout has to improve their branding and adoption.
One leg up that Yahoo has on Google in this respect is that by partnering with an established company like Paypal, Yahoo does not have to put the work into building the reputation of their merchant system along the two fronts of online retailer and customer.
Paypal has already done so with its millions of users.
It will be interesting to see if Google continues to use new techniques to attract more clicks, users and merchants into their Google Checkout system.