E-Commerce Configuration Guide : Site configuration : The SiteConfig.config vs. web.config
 
The SiteConfig.config vs. web.config
All config settings are now stored in the SiteConfig.config file as opposed to the web.config file.
The <appSettings> section is empty in the web.config file for this new version of the pages.
SiteConfig.config can be hand edited using the text editor of your choice or edited through the admin panel
 
See Site Configuration settings for a complete listing of Siteconfig.config settings.