> but after 2day shipping, you cant go back

Maybe it's a US-market issue, but I don't understand why Amazon is lauded for two-day shipping as if it is unique.

They don't have any particular delivery logistics genius except bulk-purchase discounts from the carriers.

The 'Amazon Prime' air cargo fleet is leased from an industry-standard cargo airline, nothing unique or exclusive.

And they make silly errors that show how their shipping system works; they won't ship lithium batteries ( or even DSLR cameras ) to Northern Ireland even though they have a logistics warehouse here. Because the inter-warehouse backhaul is via Royal Mail, who won't carry hazardous items.