The best business returns are usually achieved by companies that are doing something quite similar today to what they were doing five or ten years ago.
One of the ironies of the stock market is the emphasis on activity. Brokers, using terms such as 'marketability' and 'liquidity,' sing the praises of companies with high share turnover... but investors should understand that what is good for the croupier is not good for the customer. A hyperactive stock market is the pick pocket of enterprise.
The key to investing is not assessing how much an industry is going to affect society, or how much it will grow, but rather determining the competitive advantage of any given company and, above all, the durability of that advantage.