Dividend ETFs have been extremely popular with income-starved investors, but not every fund is created equal.

Different tracking benchmarks mean the funds can vary by their sector allocations, dividend yields and other important factors.

For example, Charles Sizemore at Sizemore Capital in a MarketWatch article Wednesday kicks the tires of three dividend ETFs: iShares High Dividend Equity Fund (NYSEArca: HDV), iShares Dow Jones Select Dividend (NYSEArca: DVY) and Vanguard Dividend Appreciation (NYSEArca: VIG).

HDV tracks a Morningstar index that screens for high-quality companies and tries to limit volatility. The Morningstar benchmark hunts for companies that have a wide economic “moat” or competitive advantage. It also looks for firms with solid balance sheets and tries to weed out companies with volatile earnings.

HDV’s biggest sector weighting is to healthcare stocks at 28.7% of the portfolio. [ETF Spotlight: iShares High Dividend Fund]

Meanwhile, DVY is the oldest dividend ETF having listed in 2003. The Dow Jones tracking index is comprised of 100 high-yielding stocks that meet quantitative screens. The fund has 32.2% in utilities stocks, its largest sector weighting. [ETF Spotlight: iShares Select Dividend]