It always surprizes me that large domains don't configure common mistypes of their subdomains in their DNS. For instance

w.microsoft.com
ww.microsoft.com
wwww.microsoft.com

For that website it only works as http://www.microsoft.com, or http://microsoft.com. It seems logical that they should add the common derivatives in, point them to a multi-host-header site that does nothing but redirect to http://www.microsoft.com, and voila - A lot of sloppy-typing users save a bit of time and avoid a bit of frustration.

Microsoft actually makes use of a lot of their subdomains (e.g. research.microsoft.com, msdn.microsoft.com), however for smaller sites it could simply be a wildcard entry. Even if there are lots of subdomains, the redirect logic could do some analysis of the typed in entry and figure out the likely destination. e.g. madn.microsoft.com probably wanted msdn.microsoft.com, and resrch.microsoft.com probably wanted research.microsoft.com.

Of course yafla.com isn't configured like that - I don't control the DNS in this case so I didn't have the option.