Profit ???????????
You have a bag or box, you have to pick the item and wrap it, stick a stamp on or process it thru the PO's PPI system.
We all know the PO works for sod all and staff do not expect to get paid, neither does any National Insurance payments.
Someone has to take it to the post office and queue up, or cough up £165 per year for a two day collection, 5 day collection is a lot more.
You are right, they must be running to the bank………………………………..
John S.