Yet it's also the most popular.

When it comes to international investing, the most popular vehicle out there is the iShares MSCI Emerging Markets Index (NYSE: EEM), with an astounding $41.7 billion worth of assets. Yet aside from the facts that the iShares MSCI Emerging Markets Index has been around since 2003 and that iShares is pretty good at marketing, there are two very good reasons why this ETF should not be the most popular for investors to gain emerging markets exposure.

If you own EEM or are thinking about owning EEM, then this should prompt you to ask: Are the fastest-growing parts of the world's emerging markets over the next few years going to be export manufacturing, outsourcing, banking, and globally priced commodities? And will the fastest-growing emerging markets companies be mega caps? While there's something to be said for the retail banking sector in underbanked markets such as India and Brazil, the rest of it is nonsense. Those sectors are historically where emerging markets have been; not where they're going.