Exchange-traded funds offer a convenient way to invest in sectors or niches that interest you. If you expect the communication services industry to thrive over time as our world's communications needs persist and grow, the Focus Morningstar Communication Services Index ETF (NYSE: FCQ) could save you a lot of trouble. Instead of trying to figure out which companies 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. The communication ETF's expense ratio -- its annual fee -- is a very low 0.19%. The fund is very small, too, so if you're thinking of buying, beware of occasionally large spreads between its bid and ask prices. Consider using a limit order if you want to buy in.

This ETF has performed well, trouncing the world market over the past year, but it's also not much more than a year old, making it too young to draw many conclusions about. 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.

What's in it?
Several communications companies had strong performances over the past year. Equinix (Nasdaq: EQIX), for example, soared 72%, offering data-center services to companies. Its earnings more than doubled over the past year, and revenue has been growing by about 30% or more annually over the past few years. Bears worry about its debt and spending habits, though, and fear it may be overvalued at recent levels.

CenturyLink (Nasdaq: CTL) only gained 4%, but it's also been sporting a 7.3% dividend yield lately, rewarding shareholders handsomely. As the nation's third-largest telecom company, it's focusing on broadband, fiber networks, and high-speed Internet services over wireless. Bears worry about the loss of subscribers, while bulls are pleased to see new deals being signed, such as $233 million one to provide services to the Social Security Administration. The company is not afraid to invest, either, having swallowed up Qwest and cloud infrastructure specialist Savvis.

Other companies didn't do as well last year, but they could see their fortunes change in the coming years. Frontier Communications (Nasdaq: FTR) and Windstream (Nasdaq: WIN), for example, dropped 48% and 20% respectively as they focus on serving rural areas. Frontier has been growing revenue robustly, but its earnings haven't followed suit. It does sport a hefty dividend yield above 10% but has sizable debt and falling subscriber levels. Still, some think it's now in bargain territory. Windstream, meanwhile, also yields more than 10%, having been whacked after posting disappointing earnings. It, too, though, is now being considered by some long-term investors, especially because of its investments in broadband services.

The big picture
Demand for communication services isn't going away anytime soon. A well-chosen ETF can grant you instant diversification across any industry or group of companies -- and make investing in and profiting from it that much easier.

Our current mobile revolution may dwarf any other technology revolution seen before it. To profit off of it, check out our special free report, "The Next Trillion Dollar Revolution," which names a promising company at the forefront of the revolution.