There's also nothing wrong with letting a guest who inquires and sounds serious about wanting to book know that if a request comes in before they actually book (assuming you've pre-approved) that it takes precedence over an as yet unbooked inquiry.
I once got an inquiry from a woman who sounded really cool and a good fit for my home-share. She had a couple of great reviews and we had exchanged a couple of messages and hit it off, joking around a bit about things, had a similar sense of humor.
I didn't hear back from her for 4 or 5 days, so I messaged her back to say no pressure, I just wondered if she still was interested in booking, as the tourist season was heating up and I was starting to get quite a few bookings, so I couldn't guarantee the dates she had wanted would be available much longer.
She wrote back right away, explained that she has a fear of flying (even though she flies somewhere about once a year), so always procrastinates on the plane ticket, but that yes, she still totally wanted to come, so thanks for putting a little fire under her butt. She bought the ticket, and booked my place within half an hour.
She ended up being one of my favorite guests and we still keep in touch.