Google Checkout has been around for a good year now but I'm still rarely seeing online retailers use it. It's highly recommended that all online retailers using Google Adwords should sign up to Google Checkout. The main reason is that the Google Checkout graphic is the only colourful graphic on any Google SERP and reports suggest that CTR can increase by as much as 20%-30% by having this logo displayed next to your ad.

What are you waiting for?