On balance, firms that derive less than 10% of its sales through Wal-Mart averaged 39.1% in gross margin, or the percentage of profit realized before items like fixed costs and interest expense are considered.
In the first half of the current year, the margin earned by British Gas - that is profit as a percentage of sales - was 7.2%, compared with 6.9% in the first six months of last year, and 8.9% in the whole of 2010.