I still don't understand why they can't just use a popular URL shortener like TinyURL, is.gd, or bit.ly that is unlikely to disappear overnight? It's not even l

I still don't understand why they can't just use a popular URL shortener like TinyURL, is.gd, or bit.ly that is unlikely to disappear overnight? It's not even like they're using their main domain name as their shortener to (possibly) increase their Google juice.