For example, last decade the supermarket industry enjoyed benign competition, dominated by Woolworths (AX: WOW ), and this supported decent earnings growth. Since then, competition has intensified, with a rejuvenated Coles and the expansion of Aldi and Costco (NASDAQ: COST ). All players have come to 'invest' in lower prices and a better service offering, and their investment has pressured the top and bottom-line growth for the industry. With lower barriers to entry, and the possibility of new entrants such as Amazon (NASDAQ: AMZN ), the constraint on growth arising from the competition is unlikely to abate.