Am I too impatient?

Scenario: You have an apartment for rent.

You showed it to prospective tenants (very nice people, the PERFECT tenants) at 9:30 Saturday morning.  You needed to meet them early because you were hosting a party that afternoon and evening, and you needed time to prepare.  Your perfect prospective tenants were happy to meet you that early (they’re very understanding).  They were enthusiastic about the apartment, promised to get back to you within a couple of days, and wished you well with your party.  They only took up 15 minutes of your time.

After a productive day of apartment-hunting, your perfect prospective tenants sent an email at 9:30 Sunday morning (a civilized hour) requesting an application because they would like to rent your lovely apartment that suits their needs perfectly.

Question: How long do you wait to email them back?

It is now Monday morning, and your perfect prospective tenants have not heard a peep from you.  They really want your apartment, but they also found a very nice one on the other side of the bay that would do the trick (although without the total lifestyle change they’re looking for).  They can’t leave THOSE possible landlords hanging too long, but they don’t want to shut that opportunity down because what if this apartment falls through?  They won’t know if you don’t respond.

Do your perfect prospective tenants become less perfect if they call you or send you a follow-up email?  They’re aware you had a party Saturday night and houseguests that might not have left until late Sunday.  They don’t want to be inconsiderate or pushy.  How soon is too soon?

Update: I called her, and she was very nice.  She lost track of yesterday, never checked her email, and she was just reading my message to her now.  She said she’d send over the application within the half-hour.  So once I have that, I can let our other possible place go.  Yay!