Isn’t this just Jevons Paradox applied to driving?
Now I'll order something off Amazon, then 30 minutes later think of something else I need, then 10 minutes after that get another item, and then I've got 3 separate shipments taking up 3 spaces in the lockers, because to me there's no cost to the lack of planning.
When Amazon tells me the lockers are full, I become furious.
If your orders are really 30 and 10 minutes apart, Amazon will ship them together if it can.
Although maybe it's possible they do it some of the time and I'm actually much worse about fragmenting my orders than I think :)
[0] https://en.wikipedia.org/wiki/Lewis%E2%80%93Mogridge_Positio...