The consensus estimate for Apple's (NASDAQ:AAPL) fiscal 2014 second-quarter iPhone shipments is 38 million units. But Morgan Stanley analyst Katy Huberty's AlphaWise survey estimates Apple will sell 42 million iPhones. This 4 million unit difference in estimates shouldn't be ignored -- especially since Huberty's AlphaWise survey has proved to be more accurate than consensus estimates.

Making the matter more intriguing, 4 million additional iPhone sales could push Apple into blowout territory, a place Apple definitely didn't reach in Q1. As Apple's most profitable segment, 4 million incremental iPhone sales could play a big role in Apple's bottom line, helping the company easily post two quarters of EPS growth in a row.

Fool contributor Daniel Sparks takes a closer look at Huberty's estimate, and the implications for investors in the video below.

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Daniel Sparks owns shares of Apple. The Motley Fool recommends Apple. The Motley Fool owns shares of Apple. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.