@Marie54, the practical aspect is that it might - though not necessarily - help fill some empty slots during a slow period. And there is a slight filtering possibility if you opt for the choice only to have guests who are verified and have been recommended by other hosts.
For me, though, the downside is that it's still too unpredictable. Some hosts aren't always honest in their reviews (as they fear 'revenge' responses), plus some instant bookers (such as those mentioned in these forums) have been in strange circumstances, and ended up being problematic, especially for hosts who had no Security Deposit in place and unclear House Rules.
Also, because I have work and interests outside of AirBnB - I prefer to have a little advance notice of any bookings. I find that Enquires and Requests work best for me.
I admit, though, three of my first bookings were Instant, and the guests were lovely. I only decided not to use the IB function after reading of others' experiences here.
If you do go the Instant Book route, make sure you indicate a hefty enough Security Deposit to cover possible damage to the premises, and have comprehensive, clear, and firm House Rules shown in your listing. I note that you have neither in place. Provide a copy of the House Rules as well in your accommodation. You could also re-state them in your letter of welcome to the guest.
