Inside Newegg: They give us a Tour and you a Prize

On the first floor, product is kept above and opposing the rolling conveyer. The product is grouped by frequency of purchase, not by type of product, so you will see items like motherboards on all three floors, not all grouped together in one area.

Beneath every product is a numerical readout as well as a red "Confirm" button:

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When a tub rolls by product that it needs the system stops the tub and starts blinking the confirm button beneath the product in the immediate area that needs to be put in the tub. The display next to the confirm button will give the closest worker a readout of how many of that item are needed.

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Next to every stopped tub there is a similar button and readout combination, this time telling you how many of that product have to be put in the tub. You may have two tubs roll by that both require the same motherboard, so while the counter by the motherboards will tell you that you need two, the displays by the two tubs will keep you from placing too many of the wrong item in one tub.

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Once everything is filled at this stop there's one last confirm button to hit and then the tubs move along.