I spend a lot of time looking out for undervalued products on eBay and sniping auctions. It is quite laborious. I imagine it would be most useful in this sort of shopping. Or buying tickets the second they become available, or tracking sites for cheapest air fare or hotels and completing the transaction on those sorts of things.

I don't advocate using it. I wouldn't want to. But I imagine people will use it a lot for things like this.