Apple (AAPL -0.08%) is well-aware of the fact that any new product's success or failure depends wholly on third-party developers. That's one of the reasons why the company unveiled its latest device many months in advance. Apple Watch was first shown off to the public in October 2014, and Apple released the related software development kit, or SDK, the following month so developers could get to work on designing apps for the new form factor.

Having a strong app lineup at launch is of utmost importance. So, why is there still no Facebook (META 2.44%) app for the Apple Watch?

Exterior of Apple Store in Milan, Italy

Image source: Apple.

The display is just too small
The New York Times shed some light on this conundrum over the weekend. The social network has reportedly run into challenges with designing and delivering a compelling Facebook experience on such a small display. I can sympathize with this. Among other reasons, I returned my Apple Watch because certain tasks, such as reading email, simply didn't translate very well to the Apple Watch's small display. I'd rather just use my iPhone.

Since Facebook's News Feed long ago evolved beyond merely text-based status updates, with most posts these days consisting of pictures, videos, or content links, it would be a little difficult to bring News Feed (Facebook's core product and experience) to Apple Watch. Sure, watchOS 2 will add better support for pictures and videos, but there's no escaping the small display, and there is no way to view links since Apple Watch doesn't have an Internet browser like Safari.

Interestingly, Facebook's Instagram subsidiary doesn't feel the same way. The photo-sharing service Facebook acquired in 2012 quickly jumped on the Apple Watch bandwagon.

None of this means Facebook will never have an Apple Watch app. Rather, the company doesn't feel any urgency to make one. Facebook says it is continuing to evaluate Apple Watch, much like it does with all new platforms.

Maybe some apps just won't work on Apple Watch
But perhaps the use case really just isn't that compelling. It's not hard to think of other examples of apps that would translate poorly to Apple Watch. What about Netflix? No one wants to watch House of Cards on a smartwatch. Netflix even poked fun of the idea itself with a mock advertisement for a Netflix Watch. Don't expect Netflix to stream to Apple Watch any time soon.

It's conceivable Facebook is one of these examples, especially if Facebook wants to deliver a rich and immersive News Feed experience.

Chicken, meet egg
This is just the beginning. Lacking an official Facebook app, among other high-profile absences, is a definite setback for Apple Watch's credibility. However, the new wearable already has over 7,000 apps available, and watchOS 2 will hopefully accelerate developer adoption since it will enable native apps for the first time, dramatically improving performance.

Like any new platform (even though Apple Watch is a derivative platform), Apple Watch will face a chicken-and-egg problem with developers and users. Developers and users follow one another, but which comes first? In fact, this is yet another reason why Apple should disclose approximate unit volumes when it reports earnings this week: so developers will know how large the addressable market is.