It seems there's an open opportunity: single letter domain names see only very limited use. I've just scanned through, and only x.com, q.com, and z.com resolve

It seems there's an open opportunity: single letter domain names see only very limited use. I've just scanned through, and only x.com, q.com, and z.com resolved. q.com redirects to a centurylink setup page, and z.com is a japanese media group.