Getting big returns from financial portfolios, whether through stocks, bonds, ETFs, other securities, or a combination of all, is an investor's dream. However, 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 that coveted distribution of a company's earnings paid out to shareholders, and investors often view it by its dividend yield, a metric that measures the dividend as a percent of the current stock price. Many academic studies show that dividends account for significant portions of long-term returns, with dividend contributions exceeding one-third of total returns in many cases.Boston Properties in FocusBased in Boston, Boston Properties (BXP) is in the Finance sector, and so far this year, shares have seen a price change of 21.97%. Currently paying a dividend of $0.95 per share, the company has a dividend yield of 2.77%. In comparison, the REIT and Equity Trust - Other industry's yield is 4.19%, while the S&P 500's yield is 1.92%.Looking at dividend growth, the company's current annualized dividend of $3.80 is up 8.6% from last year. Over the last 5 years, Boston Properties has increased its dividend 3 times on a year-over-year basis for an average annual increase of 8.95%. Future dividend growth will depend on earnings growth as well as payout ratio, which is the proportion of a company's annual earnings per share that it pays out as a dividend. Boston Properties's current payout ratio is 60%. This means it paid out 60% of its trailing 12-month EPS as dividend.Looking at this fiscal year, BXP expects solid earnings growth. The Zacks Consensus Estimate for 2019 is $6.93 per share, representing a year-over-year earnings growth rate of 10%.Bottom LineInvestors like dividends for a variety of different reasons, from tax advantages and decreasing overall portfolio risk to considerably improving stock investing profits. But, not every company offers a quarterly payout.For instance, it's a rare occurrence when a tech start-up or big growth business offers their shareholders a dividend. It's more common to see larger companies with more established profits give out dividends. During periods of rising interest rates, income investors must be mindful that high-yielding stocks tend to struggle. That said, they can take comfort from the fact that BXP is not only an attractive dividend play, but also represents a compelling investment opportunity with a Zacks Rank of #2 (Buy).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 Boston Properties, Inc. (BXP): Free Stock Analysis Report To read this article on Zacks.com click here.