So overnight - spot on.
Smaller mail order supplier - 3 days max, usually 2.
'Parcel Post' services via PO or other supplier should not take 7 days.

ebuyer have an interesting new slant on this.

Placed an order with them on monday for in stock items. Select
cheapest delivery charge, which, curiously, doesn't say 3 day
delivery, it says deliver by Friday 14th. Check order status next day,
says awaiting dispatch. Strange I think, if it's in stock why don't
they dispatch it?

Thursday, check order status again, still awaiting dispatch. Try to
ring them, no one seems to want to answer their expensive phone
number. Finally speak to someone and their reason for not dispatching
the parcel was that I had selected delivery on Friday; they would
dispatch on Thursday to be delivered Friday. (Wouldn't work for us; it
usually takes at least 2 days for next day delivery to get here)

So ebuyer have a new s$$m, they sit on your goods for several days
unless you pay them more.

Bill