The consensus estimate for Apple's (AAPL 0.52%) 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.

If you're interested in getting exclusive, unfiltered access to Motley Fool co-founder and CEO Tom Gardner's personal "Everlasting Portfolio" of stock picks -- a portfolio that's outperformed a stunning 99.6% of similar mutual funds over the past 12 months -- you're in luck. For a limited time only, Tom is inviting new members to apply for "early acceptance" into The Motley Fool's crown-jewel service -- Motley Fool ONE. If you're accepted, you'll be invited to test-drive Motley Fool ONE with zero risk or obligation for an entire 365 days. Simply click here to apply now... time is running out!