I have clients who invest in the SDSU area to students, nearly zero vacancy, because of the demand, proximity to campus and quickly executed turnovers. 

“ cash flow returns” almost always compare horribly to a simple bank CD after you deduct for insurance, prop taxes< vacancy, capex, prop management (or your personal time.) etc etc etc. 

They are usually looking at C or D properties that local agents tell them will “cash flow“ They usually don’t cash flow because of high maintenance and vacancy.

For that SMALL landlord, turnover/vacancy is VERY expensive because it takes them longer to prep and fill the vacancy and they are also paying the PM a fee for tenant placement whereas the large landlord is using their staff who is being paid whether they handle a turnover or not.

The rest, put you on near-worthless drip campaigns, don't understand calculating the offer price based upon rents - property taxes - insurance - MNT & Vacancy percentages, etc.DM @James Wise to schedule a chat with him!

Set aside reserves for unexpected repairs or vacancies.

They do a better job of advertising at the same rent and you avoid another month of vacancy, paying for themselves. 

What happens when you have vacancies and have to turn over units? 

If they move soon, one month vacancy would eat away any savings of a hard "no" and it's wintertime (here) where vacancy is harder to fill...I'd at least discuss with the tenant and have someone do a bid to find out what it even costs for this home.

You will have to gather more accurate operating costs (vacancy loss, taxes, utilities, insurance, mgmt fees, maintenance, HOA) to best determine potential future performance.