Google is the world’s largest search engine and this feature will help assure that Google regularly indexes all of your pages. You can use the site map to tell Google about all of your web site's pages.
To set up the site map for your 123-reg e-commerce shop, please follow the steps below:
Log into your 123-reg e-commerce package.
Select Search Engine Optimization (SEO) from the drop down.
Click on the XML Site Map link.
Click on the Submit XML Site Map button..
Now you will be able to click on the Open Google Webmaster Tools link in order to go to Google and verify the site map.