Cold calling every owner in a duplex neighborhood?

[Alexander V.]

Let's say I want to purchase a duplex, but there are few on the market. Those that do reach the market don't last long; however, duplexes are not rare in the area. I can find a neighborhood full of duplexes, look up the street at the county assessor's office, and get the contact information for every owner on any one of these streets. Many owners are now elderly and have held the property for decades.

Is there any good reason that I shouldn't just pick up the phone and cold-call every owner on the street with an offer that would be a great deal for me? Most will obviously say no, but targeting these duplex-laden neighborhoods, in many counties we could find the contact information for 50 small multi-family owners in less than 5 minutes and call all 50 in one day. It seems like anyone who does this long enough will eventually strike gold.

Has anyone tried this or a similar approach, and how did it go for you?