One is a professor at a small local college so his income is very stable and the other still has his job + we have a cosigner on his lease. 

One of my college professors once said, "when starting a business, create your budget. 

When I first moved to Prospect Hill in 2009, four of the seven condos in my condo association were vacant but of the three that were occupied my neighbors consisted of a young couple who both worked at P&G, a UC professor who had been there since the 90's, and a single dude who worked at GE in Evendale.

The professor owner went off to Peru for a dig or something.

This building is located in a city area with plenty of attractions such as universities (x3), state offices, corporate offices, retail business, restaurants, bars, etc...We are interested in marketing the rentals towards university professionals (i.e. professors) due to the presumed ease of management it will represent for us (low turnover, moderate-high salaries, presumed care of property, etc...)My question to you: How do I effectively market these units to the university professionals I am seeking to attract?

Get in, get your feet wet, learn some lessons, sometimes the hard way is the best way, but keep an eye out for those 'free professors', we're everywhere, and we want to help.

Typical renters there are younger doctors/dentists/lawyers/CPAs, temporary workers for oil & gas industries, and non-tenured college professors. 

A college professor who teaches cultural studies at the local university.

Prominent Penn State business professor Adam Grant wrote a book named “Give and Take”.

Sorry, I had to put in some law school/law dry humor as law professors would always have that answer.