It depends. My worst period is the summer. People are all on vacations nobody is ordering anything. I then switch to just robbing houses because people are not home.
Best period is the winter. People are ordering so much things over the winter.
Roughly, from my porch expeditions, I make about 2 - 3 grand a month. On a bad month it's like 500 bucks.
And man, you wouldn't believe stuff people buy online. The things I've seen.