Small storage units, are they profitable?

[Lynnette E.]

How are small storage units profitable?  One near a small 4 unit apartment I just bought has less than 50 units.  They rent from $30 to $60 a month.  About 20% have double locks, which I am guessing means they did not pay.  

I know the overhead is less than houses and apartments, only one bathroom, small office, outside electricity, lower level of expenses.  But the gross income is only slightly over $2k, and with the number of double locks, likely much less than $2k a month.  

There are several storage facilities nearby and the rents are pretty much the same, so raising the rent would result in empty units.

And it seems that it is a labor intensive endeavor.  Someone to answer the phone, someone to do the evictions, collections, figure out who damaged the door, collect rent (they do it in person the first 5 days of the month), sign up new people and close out those leaving.  

I read on here that storage units are money makers, but I do not see how it could be with the smaller units at least.  Dealing with 48 units for $45 a month average does not seem worth it.

Please enlighten me!