i also charge a deposit and state that until i receive the deposit, I am unable to hold their place. If I hadn't heard from them in a week, and you didn't ask for a deposit, I would email them and state that there is interest and you're wondering if they still the need the spot. If you don't hear back from them within 48 hours, I would move on. That's just rude of them to do that. It would teach them not to muck around when they need something from someone. I am BIG on not being taken advantage of (as most everyone probably knows by now lol) an if someone took their time getting their s**t together, that would be foreshadowing of more problems brewing.