Between January 1926 and December 2006, 41% of the S&P 500's total return sprang not from the price appreciation of the stocks in the index, but from the dividends its companies paid out.

That's right -- a cool 41%. Annualized, that amounts to 4.4 percentage points. To put it in dollars-and-cents terms, consider this: An investment of $10,000 over that stretch of time would have grown to $1,013,000 without dividends. With dividends kicked in and reinvested, however, that same sum would have been worth a whopping $24,113,000 by the end of the period.

Talk about the miracle of compound interest!

I learned most of the above from Motley Fool Income Investor, the investing service dedicated to picking the market's most promising dividend payers.

I've also learned that a dividend payout doesn't tell you a thing about a company on its own. A fat payout figure can even be a bad sign if it's the result of a stock price that's hit the skids, or if an examination of the company's cash flows indicates that its payout is unsustainable.

If you're interested in checking out more of the dos and don'ts of dividend investing, here's a must-read article on the topic. Among other things, the write-up zeroes in on a metric known as the payout ratio, and it recommends gauging that number relative to a prospective investment's asset class. While there's no magic number to look for (or avoid), the article does provide a cheat sheet for dividend payers:

  • Real estate investment trusts (REITs) with a funds-from-operations payout ratio below 85%.
  • High-growth common stocks that pay out less than 50% of free cash flow (FCF).
  • Banks that pay out less than 60% of FCF.
  • Regulated utilities that pay out less than 80% of FCF.

The article also encourages investors with inquiring minds to scrutinize the source of a company's cash, the caliber of its corporate management, and the historical reliability of the firm's payouts.

The power of dividends
What if you're a "story stock" type? Well, I'd argue that even investors who generally favor lively stocks like Sun Microsystems (Nasdaq: JAVA), Clean Harbors (Nasdaq: CLHB), or Hologic (Nasdaq: HOLX) -- none of which pays a dividend -- can reap the benefits of dividend-paying stocks. A portfolio of nothing but race cars is likely to lead to bumps in the road -- and perhaps even the occasional crash.

A fistful of comparative low-yielders such as Halliburton (NYSE: HAL) and Lehman Brothers (NYSE: LEH) may not get the job done, either: Both currently yield less than the S&P. That's also true of Baker Hughes (NYSE: BHI) and Teva Pharmaceutical (Nasdaq: TEVA).

To soften a market downturn, a dividend must be substantial enough to offer meaningful cash returns or, as Jeremy Siegel has shown, allow you to reinvest in additional shares of stock.

Want a little assistance in your quest for dividend dynamos? You're in luck. Income Investor has established a track record, having identified more than 80 top-notch dividend payers that have what it takes to beat the market over the long haul. The service's picks have outclassed the S&P's total return since inception four years ago, and they beat up on the 500's yield as well. You can take Income Investor for a risk-free 30-day spin by clicking right here.

The plain facts show that dividend-paying stocks have outperformed in the past, and they have a good chance of doing so in the future. The secret, then, is this: Reinvest those dividends, and put the power of compounding to work in your portfolio.

This is adapted from a Shannon Zimmerman article originally published Jan. 18, 2006. It has been updated.

Rich Greifner also knows the secret of making a killer smoothie. Rich does not own shares in any company mentioned in this article. The Fool's disclosure policy is no secret.