Airbnb sends prompts to the guests (and you too now, so they have plenty!). Some guests do not review at all, some do. Nothing you can do about it! They either will or wont. No, at the moment we can't see if a message has been read but it is up on the wishlist if Airbnb takes note of Host Voice. You can go and give it a thumbs up, all the new ideas are posted up there. This idea is quite far in tha back, as it went up early on. More thumbs ups and Airbnb will maybe look at it.