Similar responses to many on here already - I advertise exclusively on AW and only offer outcalls with limited availability.
I now take deposits, it is clearly stated on my profile in several places and I refuse to see anyone who won't send a deposit - The guys who email through my profile have always paid a deposit, it's the guys who text me or ring me who I seem to have the most issue with!
Stick with taking the deposit, it will be better in the long run!