Custom Domain Name Error: "The domain name you entered needs to have a CNAME pointing to mofusehosted.com"

When configuring a custom domain name for your mobile website, you may see this error:

The error is alerting you that a CNAME entry has not yet been created on the primary domain.  Once a CNAME entry has been setup on the primary domain, you will then be able to configure a custom domain name for your mobile website.