I have setup my DNS so that any sub domain redirects to the primary domain. I.E. diddlysquat.mydomain.com or whatever.mydomain.com redirects to mydomain.com. I am using keywords in my display url in my ads, I.E. blue-widgets.mydomain.com.
Is this kosher to do in Adwords? Do the sub domains that they allow you to use in your display urls actually have to exist? Are there any caveats in connection with using a Cname wildcard record to redirect any sub domain?