Apple Watch launches within a matter of months. Source: Apple

It's likely true that Apple's (NASDAQ:AAPL) forthcoming Apple Watch won't be a financial game changer for the company. At the same time, that doesn't mean the device won't be important. In fact, one Wall Street analyst believes that Apple Watch will be a notable growth driver for the Mac maker in 2015.

Word on the Street
Evercore analyst Rob Cihra (via AppleInsider) has put out a fresh research note with some estimates on how Apple's first wearable will fare in the coming year. For starters, he believes that Apple Watch will fetch an average selling price of $500.

The only official information that Apple has provided is that pricing for the Apple Watch will "start at $349," with no indication as to how high prices might go. Some have speculated that the high-end Apple Watch Edition made from 18-karat gold could cost thousands of dollars, not uncommon in the premium non-smart watch market.

Cihra thinks that Apple Watch will go on sale in March, giving the Mac maker a full nine months to sell the device throughout calendar 2015. The analyst only predicts that Apple Watch will conservatively grab 5% penetration of the iPhone installed base, comprising just 4% of 2015 revenue. Analyst estimates vary widely in terms of unit shipments, with Cihra's coming in at 18.5 million units in 2015.

However, as Apple's revenue base has grown so large, every source of revenue growth matters, and Cihra believes Apple Watch could account for 36% of revenue growth in 2015 over the prior year. Compared to the massive iPhone segment, which is now officially a $100 billion business, anything looks small. But new additions to the product lineup will help contribute to incremental growth, and in dollar terms, will still be very respectable (Cihra's estimates suggest $9.25 billion in Apple Watch revenue in the first three quarters).

It's different this time
Apple Watch is unlikely to match the iPad's rapid adoption, in part because of its reliance on the iPhone. Since Apple Watch is not a stand-alone product like tablets, its addressable market is inherently limited to the iPhone installed base. That's a necessary evil though, since no one wants to pay for yet another data plan, and the best way for Apple Watch to maintain connectivity is to piggyback on the iPhone's cellular connection. Besides, doing so will only strengthen Apple's product halo.

On top of that, fashion is a particularly important consideration when it comes to watches, and Apple has taken a decidedly fashion-centric approach to the device. The company has shown off prototypes at numerous high-end fashion events and arranged coverage from fashion magazines to build up hype and anticipation. This is something rival electronics makers are not focusing on heavily with their own smart watches, instead opting to highlight the tech side of things.

Interestingly enough, rivals could benefit from Apple's entry to the extent that the Mac maker catalyzes broader adoption and awareness of the new form factor: the whole "rising tide" effect. Investors can look forward to Apple providing more information about Apple Watch within a couple of months, as its launch approaches.

As we get better visibility into the pricing structure, and as developers continue building smart watch apps, then we'll have a much better picture of Apple Watch's value proposition and revenue potential. Until then, Wall Street analyst estimates will have to suffice.