Market Research: Gauging interest on a prop you don't own?

[Kal A.]

What are your thoughts on placing an add on craigslist (for rent) to understand the interest in a potential set of units you are looking to purchase? The property has been vacant for a year and wasn't rented before that (owner lived in one and used the other 3 as storage, so I don't have any leases to reference). Looking to understand the interest beyond just using rentometer.

Frowned upon?