Exchange-traded funds offer a convenient way to invest in sectors or niches that interest you. If you'd like to add some global dividend stocks to your portfolio but don't have the time or expertise to hand-pick a few, the SPDR S&P Global Dividend ETF (NYSEMKT:WDIV) could save you a lot of trouble. Instead of trying to figure out which global dividend stocks will perform best, you can use this ETF to invest in lots of them simultaneously.

The basics
ETFs often sport lower expense ratios than their mutual-fund cousins. This ETF, focused on global dividend stocks, sports a relatively low expense ratio -- an annual fee -- of 0.4%. It recently yielded 2.2% and contains both U.S.-based and foreign-based companies.

This global dividend stocks ETF is too new to have much of a track record to assess, but it's full of dividend-paying large-cap stocks that offer income even during market downturns. As with most investments, of course, we can't expect outstanding performances in every quarter or year. Investors with conviction need to wait for their holdings to deliver.

Why global dividend stocks?
It's best to diversify your holdings not only by market size and industry but also geographically. If the U.S. economy stalls or slides, your losses could be partially offset by investments in other economies that may still be performing well. Global dividend stocks offer an extra bonus, as dividends can be quite powerful. Internationally reaped ones can be a little more complicated than domestic ones, though.

More than a handful of global dividend stocks had strong performances over the past year. U.K.-based telecom titan Vodafone (NASDAQ:VOD) soared 54% and offers a good way to profit from Europe's rebounding economy. It's setting its sights further, too, recently winning approval to buy all of its Indian subsidiary (it currently owns 64% of it), and positioning itself to benefit more from India's growth. Bears don't like Vodafone's shrinking free cash flow, but bulls like its hefty dividend and growth prospects, and some folks wonder whether AT&T will buy Vodafone. Vodafone's first half of fiscal 2014 offered revenue and operating income slightly above expectations.

New York Community Bancorp (NYSE:NYCB) popped 34%, is near a 52-week high, and yields about 6%. Known for solid management, it has grown by more than 20% annually since its IPO in 1993, far outpacing rivals as it has acquired other banks and grown its commercial and industrial lending business. The bank's third quarter featured estimate-topping earnings (albeit lower than those a year ago due to declines in mortgage-banking income) and improving credit quality. New York Community Bancorp has attracted many with its cost cutting and risk management, but some worry that its dividend might get reduced if the bank grows larger.

Oil refiner HollyFrontier (NYSE:HFC), based in Texas, gained 23% and yields 2.4%. HollyFrontier has reduced refining capacity at its Navajo refinery due to waste water constraints, but that's a short-term problem. Bulls like the company's prospects from the Barnett Shale region. Its cash generation, solid balance sheet, and special dividends are also pluses. HollyFrontier has faced some challenges, such as oil price spreads, but it still notched a revenue gain in its third quarter.

Other global dividend stocks didn't do quite as well over the last year, but could see their fortunes change in the coming years. Canada-based utility company TransAlta (NYSE:TAC) shed 11%. It recently sported a dividend yield topping 8%, but its payout has been shrinking over the past few years. It's a significant wind-power generator, via its TransAlta Renewables subsidiary, and it's an investor in geothermal power production, too. In its last quarter, revenue grew 19%, but net income turned into a net loss.

The big picture
If you're interested in adding some global dividend stocks to your portfolio, consider doing so via an ETF. A well-chosen ETF can grant you instant diversification across any industry or group of companies -- and make investing in it and profiting from it that much easier.