Let's face it -- Apple's (NASDAQ:AAPL) iPhone X isn't the runaway success that many, including Apple, thought it would be. The iPhone X didn't spark a surge in iPhone unit shipments during the company's peak quarter, nor does the phone appear to be providing the company's iPhone business with the kind of lasting power into subsequent quarters that some had hoped for. 

The silver lining is that the iPhone X carries a significant premium to previous iPhone flagships, so Apple's iPhone business should enjoy year-over-year revenue growth throughout the current fiscal year as iPhone X shipments lift iPhone average selling prices

Apple's iPhone X.

Image source: Apple.

In this column, I'd like to go over two things that could boost Apple's business and ultimately translate into a higher stock price for the company. 

1. A cheaper, modern iPhone

In September 2017, Apple announced three new iPhones: iPhone 8, iPhone 8 Plus, and iPhone X. The iPhone X sported an all-new design with some interesting and unique features like Face ID, but it was extremely expensive. 

The iPhone 8 and iPhone 8 Plus, which came in at more traditional flagship iPhone price points, had dramatic internal upgrades but looked quite similar to the prior three generations of devices. The similar aesthetics to older iPhone models, especially as competing smartphones adopt sleeker aesthetics, probably hurt interest in the company's mainstream iPhone line. 

This year, Apple is expected to launch a replacement for both the iPhone 8 and iPhone 8 Plus that'll look similar to the current iPhone X, but be a little bit larger, lack 3D Touch, feature a cheaper construction, and use the same, less advanced display type that's found on the iPhone 8/iPhone 8 Plus. That phone likely will be more compelling to a wide swath of current iPhone users than the iPhone 8 and iPhone 8 Plus, which could lead to accelerated iPhone upgrade activity. Apple also stands to gain share against Android-based flagship devices with such a product. 

If the new lower-cost iPhone proves successful in achieving both of those goals, it would boost Apple's iPhone shipments, revenue, and profits -- perhaps significantly. 

2. A bigger iPhone X

Apple's iPhone X is very similar in physical footprint to the standard iPhone 8, though it has a larger display thanks to the edge-to-edge design. The display on the iPhone X is larger than the one on the iPhone 8, and in terms of screen real estate, is about as large as the one on the iPhone 8 Plus. 

However, the iPhone X's display is significantly narrower than that of the iPhone 8 Plus, so while the screen area of the latter is similar to that of the former, many of the features -- like split-screen multitasking in certain applications that the iPhone 8 Plus is capable of -- aren't enabled on the iPhone X. 

It's only natural for Apple to plug the gap in its iPhone portfolio this year by introducing a device that's similar in size to the iPhone 8 Plus but has a larger, edge-to-edge display. Several credible reports from Bloomberg, KGI Securities, and others indicate that Apple is planning to launch a larger version of this year's iPhone X that fits the bill. 

I think such a device will be quite popular among high-end iPhone buyers and could even entice current Android-based "phablet" users to switch over to the iPhone. Moreover, such a device is likely to command a high selling price -- I'd expect it to start at no less than $1,099 for the entry-level model -- so the better the sales of such a device, the faster Apple's iPhone revenue will grow in the coming product cycle.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.