Mr Roberts thinks that new entrants, such as online grocers who visit consumers' homes each week to drop off orange juice and toilet paper, could develop more efficient ways to deliver parcels and packages than either the traditional postal firms or the specialist express operators.

ECONOMIST: Europe��s last post

Some have said Saturday letter delivery could be ended if the Postal Service kept delivering packages and express mail on the weekends, as was planned.

WSJ: Postal Service Delays Plans to End Saturday Delivery

Across the pond in Europe various national postal operators and global courier, express and parcel operators have diversified their offerings to various degrees and in some cases through geographic expansion.

FORBES: Never Go to the Post Office Again

At TNT, a Dutch postal operator, shareholders won a battle to get the firm to separate its express business from its mail division, but the company added unpopular anti-takeover mechanisms to the express part.

ECONOMIST: European corporate governance