As a point of comparison, Tesco, one of the UK's largest companies, also has a 3% profit margin. They do take £1 in every 7 spent in the UK high street, so it o

As a point of comparison, Tesco, one of the UK's largest companies, also has a 3% profit margin. They do take £1 in every 7 spent in the UK high street, so it obviously works quite nicely for them. So at volume, it is very sustainable.