That only really works for companies local to you. Plus, it ignores that at many large companies a referral just means an extra tag in the ATS that might or might not help you bubble up.
I think by referral the poster meant a contact within the company passing a resume directly to the hiring manager. I'll have someone put me down as the referrer when they apply online, but I also ask them to send me a resume and I make sure it goes to the hiring manager.