Been looking at a nice condo unit in a very popular location that isn't selling because the property is too loud. 

I removed Airbnb from this Google Trends search because it depressed all the other searches because it is most popular in Hawaii.

It can be worth some money (Midwest farm land is about $160/ac per year in rent) and obviously land on a popular lake, the strip, or NYC can be be north of a $1m/acre.

Thats a great idea @Chris Mason food truck type "depot" areas around here are quite popular.  

Areas such as Liberty, Ferndale, Swan Lake, Woodridge, Monticello, and Woodbourne are quickly becoming popular among buyers.

For example I have house hacking clients in Malibu doing STR and the city imposes a 15% gross income tax.The popular areas (Joshua Tree, Big Bear, etc.) from what I am hearing are over saturated.

I hear Goat Yoga is getting pretty popular.

Shoot, you could own 10 doors and be on your way to an early retirement, my friend.I know this will not be a popular concept here, but consider it anyway.

It's not as popular as traditional REI because it's not as lucrative as the Internet suggests.

If you're looking for a software I know that Propstream is a popular option that pulls records from public sources that you can filter for sellers who might be motivated.