Usually the existing owners are commercial buyers.Usually everyone knows everybody else that run businesses.Some owners own 30 properties are more which is good because more than likely they are qualified to purchase some more.
First time commercial buyers are like anyone else they are HARD to qualify,if they want a small business loan get ready for a massive headache.
You can also get a list of the people who filed for new business liscenses,this is what advertisers do to hit up the newbees.Usually they get the liscense first so some won't have acquired a space yet.
When someons asks you about franchising you have to know the answer,some restaurants for instance will let you open as long as you have the cash.
Others like Mcdonalds require extensive training and they have control over the site selection process and also require you to be a day by day participant in the restaurant.
Waffle House won't even let you open one up unless you work for them,it's all in house.