Don't stop marketing and showing until you have a signed lease

When the property first became available, I showed it to someone who liked it, gave me the check (application fee) and advised she will fax the application on Tuesday (Monday was a holiday). I knew she was going to qualify based on the information I collected about her (she just sold the house due to divorce, good income, etc). I closed the case and stopped marketing- only to find out a week later that she decided to buy a house instead.

Don't make this mistake and continue marketing and showing the property untill you have a signed lease. Regardless of what they promise to do and how bad they want it, keep showing.