Those who are rich or relatively rich in America are responsible for much of our consumption. That's according to an article at seekingalpha.com, which states that roughly 60% of total U.S. spending is done by the top 20% income earners.

That statistic might make you wonder what that elite group spends its money on. And if so, you're in luck, because you can now invest in companies that generate at least 60% of their revenue from sales of luxury goods. It's all thanks to a newly launched exchange-traded fund, called the Claymore/Robb Report Global Luxury fund. Trading under the ticker ROB, the fund aims to offer the returns of the Robb Report Global Luxury Index, which includes between 20 and 100 global companies. (It recently held 42.)

The pros
Whether ROB is a suitable investment for you depends on your view of America and the world. If you expect the rich to keep getting richer, or if you see the ranks of the rich growing in developing nations, you might reasonably expect that their consumption levels will similarly increase. If that happens, these luxury purveyors will probably see their top lines continuing to grow. If that's the case, then you can probably imagine even more money flowing into luxury providers.

The fund offers some other advantages. For one thing, you get instant diversification into up to 100 companies. It also features both American and international companies, ranging from Mercedes maker Daimler (NYSE:DAI) to luxury retailers such as Tiffany (NYSE:TIF), Coach (NYSE:COH), and Nordstrom (NYSE:JWN). About a quarter of its holdings are U.S.-based, with another quarter hailing from France, and smaller fractions based in Switzerland and Germany.

The cons
Why might you want to skip this investment? Well, a main consideration is how it fits in your overall portfolio. You may already own a number of its top holdings in your other funds, or perhaps as individual stocks. You may also be turned off by its fees. The fund's website notes that its annual expense fee is currently capped at 0.70%, but actual expenses may be higher, and higher expenses hurt your returns. Remember that with broad-market index funds, such as Standard & Poor's Depositary Receipts (SPY), you can enjoy expense ratios as low as 0.08%!

You might also want to wait until you see a longer track record for this index. Or you might conclude that you'd rather invest in industries that hold the promise of growing more rapidly than consumer discretionary products and financial services -- which is what ROB focuses on. Some of its holdings, such as Goldman Sachs (NYSE:GS), Credit Suisse Group (NYSE:CS), and UBS (NYSE:UBS), might end up doing poorly if problems in the financial industry continue.

Don't think you know all you need to know about this niche, either. For one thing, inflation appears steep for luxuries. The folks at Forbes, for example, have been tracking the value of a basket of luxury goods over time and found it rising 6% between 2006 and 2007, more than double the rate of inflation.

My bottom line is that while I find this new ETF interesting, I'm not drawn to it, at least not yet. There are more exciting ETFs -- and more exciting mutual funds -- out there. And if you're interested in jet-setting across the world for the most promising international investments, I invite you to test-drive, for free, our Motley Fool Global Gains newsletter service.

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Meanwhile, I encourage you to learn more about ETFs by visiting our ETF Center. It features info on how ETFs stack up against mutual funds, how to develop an investment strategy with ETFs, how to avoid pitfalls, and how to steer clear of ETF impostors.