Whether it's through stocks, bonds, ETFs, or other types of securities, all investors love seeing their portfolios score big returns. But when you're an income investor, your primary focus is generating consistent cash flow from each of your liquid investments.While cash flow can come from bond interest or interest from other types of investments, income investors hone in on dividends. A dividend is the distribution of a company's earnings paid out to shareholders; it's often viewed by its dividend yield, a metric that measures a dividend as a percent of the current stock price. Many academic studies show that dividends make up large portions of long-term returns, and in many cases, dividend contributions surpass one-third of total returns.Principal Financial in FocusPrincipal Financial (PFG) is headquartered in Des Moines, and is in the Finance sector. The stock has seen a price change of 34.37% since the start of the year. The financial services company is currently shelling out a dividend of $0.61 per share, with a dividend yield of 3.66%. This compares to the Financial - Investment Management industry's yield of 1.58% and the S&P 500's yield of 1.36%.Looking at dividend growth, the company's current annualized dividend of $2.44 is up 8.9% from last year. In the past five-year period, Principal Financial has increased its dividend 5 times on a year-over-year basis for an average annual increase of 6.80%. Looking ahead, future dividend growth will be dependent on earnings growth and payout ratio, which is the proportion of a company's annual earnings per share that it pays out as a dividend. Principal Financial's current payout ratio is 44%. This means it paid out 44% of its trailing 12-month EPS as dividend.PFG is expecting earnings to expand this fiscal year as well. The Zacks Consensus Estimate for 2021 is $6.49 per share, with earnings expected to increase 31.38% from the year ago period.Bottom LineInvestors like dividends for a variety of different reasons, from tax advantages and decreasing overall portfolio risk to considerably improving stock investing profits. It's important to keep in mind that not all companies provide a quarterly payout.Big, established firms that have more secure profits are often seen as the best dividend options, but it's fairly uncommon to see high-growth businesses or tech start-ups offer their stockholders a dividend. Income investors have to be mindful of the fact that high-yielding stocks tend to struggle during periods of rising interest rates. That said, they can take comfort from the fact that PFG is not only an attractive dividend play, but also represents a compelling investment opportunity with a Zacks Rank of #2 (Buy). 5 Stocks Set to Double Each was handpicked by a Zacks expert as the #1 favorite stock to gain +100% or more in 2021. Previous recommendations have soared +143.0%, +175.9%, +498.3% and +673.0%. Most of the stocks in this report are flying under Wall Street radar, which provides a great opportunity to get in on the ground floor.Today, See These 5 Potential Home Runs >>Want the latest recommendations from Zacks Investment Research? Today, you can download 7 Best Stocks for the Next 30 Days. Click to get this free report Principal Financial Group, Inc. (PFG): Free Stock Analysis Report To read this article on Zacks.com click here. Zacks Investment Research