Exchange-traded funds offer a convenient way to invest in sectors or niches that interest you. If you expect India-based companies to thrive, thanks to the nation's technological talent and booming population, the WisdomTree India Earnings (NYSE: EPI) ETF 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 several dozen of them simultaneously.

The basics
ETFs often sport lower expense ratios than their mutual fund cousins. The India ETF's expense ratio -- its annual fee -- is a not-so-low 0.88%. However, that still beats many India-focused mutual funds, which charge as much as 2%.

This ETF has performed well, but it's also very young, with just three years on the books. It fell sharply after its 2008 inception, nearly doubled in 2009, gained 20% in 2010, and is up 11% over the past year. As with most investments, we can't expect outstanding performances in every quarter or year. Investors with conviction need to wait for their holdings to deliver. With a relatively low turnover rate of 33%, this fund isn't frantically and frequently rejiggering its holdings, as many funds do.

In another appealing feature, this India ETF weights its components by earnings, rather than market capitalization, favoring the companies raking in money over those that aren't.

What's in it?
Several of this ETF's components made strong contributions to its performance over the past year. Tata Motors (NYSE: TTM) gained 40% and is expected to grow at a much faster pace than car companies Ford (NYSE: F) and Toyota. Other holdings include India's largest banks, HDFC (NYSE: HDB) and ICICI (NYSE: IBN), up 8% and 18%, respectively. Their near futures may not be as rosy as their near pasts, if interest rates keep rising in the emerging nation.

Business and IT consulting and outsourcing giants Infosys (Nasdaq: INFY) and Wipro (NYSE: WIT) gained 10% and 7%, respectively, over the past year, boosting the ETF at least a bit. They may not add as much in the near term, though, deemed fairly or overvalued at this point by some observers. Wipro is adding oil and gas IT capabilities, which may help its growth prospects.

The big picture
Opinions on India's prospects for investors are mixed. If you're bullish on it, and there's ample reason to be, a well-chosen ETF can grant you instant diversification across the country -- and make investing in and profiting from it that much easier.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.