You might want to try something that I make a habit of doing....
1st contact (usually by email); are they a good fit (age group, pickup/drop off times fall within my schedule/behaviour or otherwise issues?).
2nd contact: If yes to above, I then email them: A copy of my contract, handbook and a short video of our space. At this point I stress to them to take their time to review everything and to call when they are ready to set up a time to meet.
3rd contact: Meet in person. Again, I stress for them to feel free to take their time in deciding...in every case they have signed on the spot at this point, but I, at least feel that I have not pressured them.