Measuring rental demand?

[Account Closed]

Hi investors,

Would greatly appreciate your advice on how to measure if there's enough rental demand in a town. 

I'm looking to buy my first investment property in the suburbs of Detroit (e.g. Royal Oak, Ann Arbour). There are a few dozen houses with my target number of beds/baths/sqft that have been listed for rent on Zillow for 2+ months with 0 applicants.

Is this normal or is it a sign that's there's not enough demand for rentals? How do you measure rental demand before committing on a market?

Gratefully,

Hilary