Oh, you are all soooo wrong about restaurants!
I average $3000 to $4000 a month out of a burrito restaurant. Typically 24x60 photos-on-canvas of *local interest scenes* in gonzo frames. Just plain old coated canvases. I wipe off the red and/or green chili stains once in a while. Only one seriously damaged piece in 4 years.
But to sell it's gotta be big, it's gotta be flashy, and it's gotta be
local interest. But forget the prissy little merely-pretty pictures, how futile are those.
The only contract is verbal. I will never let there be empty spaces, I will bottom align all pieces (sigh), I will assure the pieces are completely presentable at all times, I will not use the walls as storage for dull-witted pieces, and I will not hassle customers when putting up or taking down pieces. And I get 100% commission. I am positively fanatical about adhering to these terms. I have never, ever bothered the owner about anything. And I give small framed pieces to everybody who works there at Xmas.
And I handle all sales, to buy the piece the customer calls the telephone number on the title card. This is a slight disadvantage, I would probably make more sales if the restaurant would handle the transactions. But this is very important to the owner since she just doesn't want to hassle sales and taxes outside her own business. But what the heck, I have to deliver these large pieces anyway and it builds my direct client base.
For instance, everybody in my town sees this mountain every day. And they KNOW they need to have this 30 x 80 affordable beauty hanging above their sofa or in their boardroom or in their reception area. This is the kind of local interest stuff that sells.