Forget what you heard about Apple's (Nasdaq: AAPL) ho-hum fiscal first quarter. Selling 16 million iPhones? That's peanuts. R.W. Baird analyst William Powers expects the Mac maker to sell 25 million handsets to Verizon (NYSE: VZ) customers this year.

The Wall Street Journal's AllThingsDigital blog first reported the news Friday. Apparently, Powers and his team surveyed 1,000 potential buyers, and found that 29% of current Verizon feature phone owners and 25% of smartphone owners were either "probably" or "definitely" planning to switch to the iPhone. Combined, that equals 23.8 million switchers. Mixing in another 5.6% of survey respondents brings the total to nearly 25 million, the Journal reports.

If Baird's right, it would explain why Verizon has joined peer AT&T (NYSE: T) in paying Apple rich subsidies in exchange for selling the iCandy. Verizon could reap more than $6.6 billion in iPhone revenue in its first year. Let's dig into the math:

  • Feature phone upgraders would account for 19 million iPhones over the next three months, Baird estimates. If Verizon's upgraders match those historically observed at AT&T, they'll double their monthly payment to about $90 per month to get the device. Assuming that all 19 million will have transitioned by May, that's $45 a month in incremental revenue, earned over seven months from 19 million subscribers, for a total of $6 billion.
  • Smartphone switchers would account for another 4.8 million new handsets, Baird says. However, because these are current smartphone customers, it's unlikely that Verizon would see a revenue boost. Big Red might even take a loss. According to data compiled by Pageonce, iPhone owners have the lowest average monthly phone bill. Windows Mobile users pay the most, with Android users ranking second and BlackBerry users a close third, Pageonce says. Let's call this a net-zero benefit.
  • Finally, AT&T switchers could add another 1 million subscribers, Baird estimates. Presuming they're all active by May, that's $90 a month in incremental revenue, earned over seven months from 1 million new customers, adding another $630 million to the pile.

Last year, Verizon booked $63 billion in wireless revenue from 94.1 million subscribers. The iPhone alone could increase that figure by 10%.

But all this assumes Baird's survey of 1,000 potential iPhone owners is an accurate reflection of real-money demand. I'm not so sure it is, but I've also had my say. What do you think? Please vote in the poll below, then leave a comment to explain your thinking. You can also rate Verizon in Motley Fool CAPS.

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Fool contributor Tim Beyers is a member of the Motley Fool Rule Breakers stock-picking team. He owned shares of Apple at the time of publication. Check out Tim's portfolio holdings and Foolish writings, or connect with him on Twitter as @milehighfool. You can also get his insights delivered directly to your RSS reader. 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 owns shares of Apple, in which it has also written puts. The Fool is also on Twitter as @TheMotleyFool. Its disclosure policy like its days like its eggs: sunny-side up.