I believe most Tesla YouTube videos include referral links as owners get a monetary kickback for the referral. It wouldn't surprise me if enthusiasts that haven't bought a Model S yet are going to go through one of those links as opposed to an outright purchase from the website, especially if the supercharging limits are known.

You can only do five referrals per code.

I wonder. It depends how they do it. If each owner only has one referral to give, it would be harder.