Agreed that this is a better solution but the point of the site is to get from 0 to 1 customer as simply as possible and setting up a DNS server adds a complication. Another HN user recommended opennic, though - I might change the recommendation from Google to something like that.

I see. OpenDNS would be another, but I'm not sure who owns them (iirc they were bought by someone that made me go "ah, no more OpenDNS for me" but I might misremember). Opennic I didn't know of, I'll check that out next time I need a resolver somewhere :)