I suspect that a very large fraction of purchases at the bin store are impulse buys that provide a temporary serotonin hit.

Then the purchaser gets home and realizes that no, in fact they do not need a frog-themed toaster whose mouth is too small to fit a normal slice of bread, and they throw it out.

You could look at this as an abitrage opportunity where a business throwing out bulk waste has to pay for it, but if you distribute it to individual citizens whose trash bin still has a bit of room in it, you can throw it out for free.