For many investors, dividends can become a realistic source of income after retirement. For example, if you owned $1 million worth of Realty Income (O 0.48$4,750 per month or $57,000 in cash every year without having to work. That's significantly more than the U.S. median income of$42,220.To be fair, most Americans don't have $1 million in cash lying around. However, accumulating this amount of money is very doable over the long term. The key is starting ...