April 21st! Mark the date. Circle it. Set your alarms, and put your crash helmet on. If you’re not mobile-friendly that is. Because April 21st is the day that your search engine rankings die. It’s been called the mobile-friendly apocalypse, mobile-friendly meltdown,a there’s even a hashtag, #mobilegeddon, for it, and indeed the world may end for your business. But bad things will only happen if you’re not mobile-friendly.