Scott The Book on Flipping Houses, The Book on Estimating ReHab Costs http://www.biggerpockets.com/flippingbookYou might consider Niche or Specialized Housing like student housing, tourists or vacation rentals.

I'm considering a Direct mail campaign, but my area is a heavy tourist area, with about 40-50% being second homes and seasonal rentals, so absentee owner lists are pretty difficult to weed through, obviously I will need to focus on NOD's and Tax default, and death notice/estate/probate lists, anyone have experience in a heavy second home market?

Conde Nast Traveler recently announced their 'Top 10 Trips everyone in the US should add to their bucket list' and it features some impressive vacation regions and activities:- Hot Air Ballooning, New Mexico- Bluegrass Trail, Virginia- Visiting Point Dume Malibu, California- Horseback Riding, Wyoming- Airboat tour Everglades, Florida- Winter expedition cruise, Alaska- Spiral Jetty, Utah- Camping In Acadia National Park, Maine/Rhode Island/Massachusetts - Trekking the Bayou, Louisiana - Wine country, Willamette Valley & Napa Valley Oregon/California 

We do have 6 million tourists a year coming here for the history which is not going to change. 

I was actually thinking about looking at a 4 unit multi family downtown as close to desirable tourist destinations as possible, and then renting out 3 of the units on airbnb while living in the 4th. 

Location is key, is it a tourist area, in a city near a college dorm and rentals, what's the market?

Sanibel and Captiva are a big draw for tourists, and they will not be accessible by car for a long time (I'd have to guess at least a year to rebuild that infrastructure). 

.🥾 Explore Goshen Pass🍷 taste wine at Jump Mountain Vineyard🎣 fish on Lake Merriweather📖 Book your tranquil escape today!

This can make it an appealing location for residents and tourists alike.

We manage a 100 properties in a tourist area and comparable properties listed on both platforms have 65% occupancy while properties only on AirBNB have 55% occupancy".