| Google views subdomains as a separate domain as the main one.
red.barndoor.com would be a completely separate site (and domain) than barndoor.com in the eyes of Google. While it might be good for typing in, you may want to go with barndoor.com/red and maybe forward red.barndoor.com to the folder.
Unless they can hold their own or it is meant to be a separate site, I wouldn't bother with subdomains. |