[source: http://www.fool.com/investing/general/2015/02/13/the-extraordinary-story-of-americas-most-successfu.aspx]

It comes down to two factors, both of which are paradoxical and relevant to all investors in all industries.

1. Fear, disgust, hatred, and outrage toward a business is good for shareholders.
A lot of investors (understandably) want nothing to do with tobacco companies. Some pension funds are barred from owning them. And then there's the constant threat of litigation, which has hung over the industry for decades.It adds up to millions of otherwise enterprising investors who won't touch tobacco stocks.

Low investor demand keeps tobacco-stock valuations low. Low valuations lead to high dividend yields. And high dividend yields, compounded over decades, add up to massive returns.

The more hated an investment is, the higher future returns are likely to be. The same is true vice versa. This is one of the most difficult investing concepts to come to terms with, but probably the most powerful.

2. Tobacco companies barely innovate. That keeps them sustainable.
Innovation is exciting because it promises something new. New products. New markets. A new future.

But it's expensive. And even if you're great at it -- like Apple (NASDAQ: AAPL  ) is -- you'll probably stumble one day.

The products Apple made just five years ago are utterly irrelevant today. The company has to reinvest itself every few years, continuously coming up with breakthrough products that blow us away. What are the odds it'll keep innovating consistently at the rate it has for another 20, 30, 50 years? Pretty low, I'd say. Even the best players strike out from time to time, and ruthlessly competitive markets show them no mercy. It's rare that a leader sticks around for more than a decade in industries that undergo constant change.

Companies that make the same product today they did 50 years ago are different. They don't innovate, but they don't have to. It's a boring business, but it can be beautiful for shareholders because it keeps the companies chugging along for decades, if not centuries.

The ridiculously large gains from compound interest occur at long holding periods. They key to building wealthy isn't necessarily high returns, but mediocre returns sustained for the longest period of time. You typically find that in boring companies that don't innovate, and sell the same products today that they did 50 years ago, and will likely be selling 50 years from now. Food, soap, toothpaste and, yes, cigarettes are good examples.