Sites that save and restore shopper IDs by means of URLs or cookies should use the GetShopperID method of the Page object instead of the GetShopperID method of StandardSManager. Sites using the AUO do not require these methods.
The GetShopperID method returns the shopper ID from a cookie stored on the client system or from a URL.
StandardSManager.GetShopperID(Context)
If no shopper ID is stored on the client system, GetShopperID returns an empty string.