A firm with a small share of total volume that competes with an incumbent in delivery only, will find its unit cost high relative to the incumbent, even if the competitor pays no wage premium and or is more efficient.
Everyone should switch to email to make life easier. 
mnli hypothesis: Everyone should switch to email to make life easier.  premise: A firm with a small share of total volume that competes with an incumbent in delivery only, will find its unit cost high relative to the incumbent, even if the competitor pays no wage premium and or is more efficient.