I strongly believe that moat as a concept is somewhat illusory. All businesses tend to become commodity after a point, when more and more competition sets in. Look at the business history over a 100 year period and you will find it very difficult to find companies which have sustainable business advantage. A case in point is newspapers. Even the great and venerable Warren Buffet used to think that his holding in Washington Post to be a bullet proof investment because in his own words "You can't beat a good newspaper business franchise". However, 50 years down the line Washington Post is struggling to make money. Times change, consumers change, preferences change. As in life, there is nothing permanent about business, other the promise of change.