First, always be very clear in your profile instructions as to how your guest will get in (lock box, meeting you, etc.). That said, I work with Cityami, a property manager made specifically for home sharing - and we have this all the time. Guests book your home, and don't read anything else. They also don't respond to anything before. The only thing you can do is message them on the platform, sms, and call. If they don't get back to you, they certainly will at check-in time! I've had guests who didn't respond just show up and say "I'm here. Can you let me in?" I'm not sure why guests assume someone is always at the apartment waiting for them, but they do. If you use a lock box (highly recommended), just send them the instructions. If not, let them know you're glad to hear back from them and are on your way. These things happen more often than not. You'll save yourself a lot of stress planning and preparing for it rather than trying to control it.