Xoom (UNKNOWN:XOOM.DL) may not be a household name to many, but the online money transfer service is growing its customer base quickly, which should have investors' attention. Money transfer services represent a tremendous global market opportunity today, particularly in U.S. outbound remittances.

Xoom eschews a capital intensive network of physical locations in favor of technology, giving it a capital-light business model that brings more profitability down to the bottom line. But perhaps the most compelling part of Xoom's business is its proprietary risk management model, which allows for immediate funding for its customers while mitigating the risk of reversals (losses) for the company at the same time.

Investors interested in Xoom will want to pay attention to the total transactions the company is making, along with the gross sending volumes. Growth in these two metrics are indicators that demand for Xoom's services are on the rise, and that's good news for investors.