I took my first investing class as a teenager, and one moment stands out in my memory. A fellow student asked the instructor, a stockbroker, about dividends.

"Dividends?" he asked. "I'm trying to make my clients wealthy. You don't do that waiting for tiny checks in the mailbox every quarter."

Even then, I had enough horse sense to know he was wrong. Paying attention to dividends is exactly how you become wealthy over time.

Wharton professor Jeremy Siegel made a wonderful discovery in his book The Future for Investors. The greatest long-term returns typically don't come from the most innovative companies, or even companies with the highest earnings growth. They come from companies that happen to crank out dividends year after year. Simply put, since the 1950s, "the portfolios with higher dividend yields offered investors higher returns."

Market commentary regularly centers around price gyrations, yet dividends have historically accounted for about half of total returns.

Take Family Dollar Stores (NYSE: FDO), for example. Since the early 1970s, the company's share price has increased 14,300%. But add in reinvested dividends, and total returns jump to nearly 28,000%:

Source: Capital IQ, a division of Standard & Poor's. 

The results are similar for other retailers like Target (NYSE: TGT) and Wal-Mart (NYSE: WMT); reinvested dividends skew both companies' total returns dramatically higher. If you're a long-term shareholder, don't worry about daily share wobbles. Devote your attention to those dividend payouts and your commitment to reinvest them.

And how do Family Dollar Stores' dividends look? At 1.4%, its yield is below the market average, but what the company lacks in power it makes up for in stamina: Dividends have been paid uninterrupted, and indeed raised, every year since 1976. That performance has earned it a spot on the S&P's coveted Dividend Aristocrats Index. Over the past five years, dividends have used up an average of just 20% of free cash flow. That's a low figure that should aid in continuing the company's history as a dividend dynamo well into the future.

To earn the greatest returns, get your priorities straight. What the market does is less important than what your company earns. What your company earns is less important than how much it pays out in dividends. And what it pays out in dividends is less important than whether you reinvest those dividends.