Buford Highway is like a roach superhighway, all those restaurants packed together and the bugs just move between buildings when one place gets sprayed. I see this same thing with weeds in my yard. I spray the tops with the store stuff and they pop back up two weeks later because the roots never died. The gel bait works because the roach takes it back to the nest and kills the whole family, not just the ones you see running. That's why the spraying made it worse for you, all it did was push them deeper into the walls where they kept breeding. Week three with no roaches tracks with the bait cycle since it takes a couple weeks to wipe out the colony, so your guy knew what he was doing.

That bit about the fountain pump keeping the arcade machines alive is wild and kind of sad at the same time. Real shame what happened to those old malls.