An example

George is a wine importer and has most of his purchases in Euro. To cover himself from fluctuations of the currency he agrees  a fixed exchange rate for his forecast import for the next twelve months. He then can be worry-free with setting his wine bottles price and consequently have a profit margin which does not get affected by the Euro appreciations. Hence he beats the competitions when Pound is low by maintaining sell prices vs competitors compelled to raise the price accordingly.