How Scout works
The four-step version is on the front page. This page will go deeper; the part that matters most is below.
Detection is shared. Buying is not.
Everyone running Scout contributes what their browser sees. That is why you get told about a restock your own machine never looked at, and why the network gets better as it grows.
Carting is the opposite. It happens only in your browser, in your own session, on your own account, with your own payment method. PackFresh never holds your retailer login or your card, and never completes a checkout.
The practical consequence: if the machine running your extension is asleep, alerts still reach you but nothing will be added to your cart. Your dashboard says which state you are in rather than leaving you to guess.
A cart line reserves nothing
On a real drop the item is winnable by anyone until checkout completes. Scout gets you there first; it cannot hold it for you.