I've heard of reducing a Bob Ross postcard to just doing it with 4 fast food places. You print 2000 of a sheet that has a coupon for each shop, and each store commits to putting one in every bag/tray order they send out.
The twist we add now is that you do it with 3 places, printed on a bookmark. I got a quote for 2000 2x6 hi-gloss UV one-sided bookmarks for less than $200, shipping included, at the first place I checked.
$900 revenue ($300 per business)
-$200 printing and shipping
$700 profit. Drop off the bookmarks at the three locations and you're done.
Why mention such a small change: (1) Commit 3 businesses and get paid. Quicker and more flexible: do it 3 times a week and earn $2100. Or if you're like me, barter to get food delivered to your house a couple times a week while still turning a profit. (2) Much easier to tear/cut to redeem the coupon than a square sheet. (3) Bookmarks don't get bent as easily as square sheets. They're portable and fit in nearly any bag or tray without a problem. (4) Easier storage for the shops, minor point.
(EDIT: You don't have to tell anyone they're bookmarks. You don't really want people keeping them between pages to begin with.)
I included a 10-second MS Paint concept, which probably isn't even needed. Like I said at the start it's really a lot more basic than a lot of people would be used to, but if someone needs cash now (or if they're terrified of cold walking and want a gentler start), maybe it could help someone.