After months of delays, Leap Motion finally has delivered its gesture-recognition hardware to customers who pre-ordered it (I ordered mine 14 months ago). Did Leap just do for gesture-controlled screens what Apple did for touch-screen inputs?

At South by Southwest this year, Leap offered the most exciting tech demo of the festival, and it probably would have run away with the most buzz if Grumpy Cat's meet and greet hadn't upstaged the startup. Here's what marketers really need to know about Leap now that it's in market:

The first generation's just a signal. Apple is one of few companies that can create transformative, blockbuster first-generation hardware products, as it did with the iPhone and iPad, but even Apple creates products like Apple TV that are lackluster at first. Even as Leap garnered more than nine million views of its preview video for the $80 device, this doesn't guarantee that it will be a long-term winner.

Shipping products is tougher than shipping demo videos. The reviews of Leap's product now are coming out. Instead of just imagining a future of gesture-controlled screens, as popularized in the science-fiction film "Minority Report," there's the reality of the buggy software, the buggier apps that debuted with the device and a gadget that works so-so at a desktop station, but not so well with a laptop. Early adopters can satisfy their curiosity, but this isn't yet ready for the masses.

There are risks for the first-mover brands. Disney sells a Wreck-It Ralph racing game in Leap's Airspace app store for $1.99, and The New York Times offers a free news reader. These brands get to be featured as first movers, but there's the downside of the apps not working optimally. Worse still, they may be forgettable. Even if the apps loaded faster, it is far easier to scan the news on a laptop or smartphone, and racing games are more intuitive on a smartphone, or on a gaming console like the Xbox. Marketers need a high risk tolerance to take part in such pilots.

Most of these Leap Motions will soon be clutter in a desk drawer. There are few cases right now, whether for business or entertainment, where gesture is better suited to the task than a mouse or touch. Most people who bought the $80 device can either rationalize the purchase as worth the risk or submit it as a business expense. Then they can toss these aside and wait for the next version.

Screen size matters for gesture controls. The Xbox Kinect, which became the fastest selling consumer electronics device ever when it launched, remains a remarkable first-generation product. It's designed for a much larger screen, and people are supposed to use it from eight to 10 feet away. In "Minority Report," gesture screens were used essentially in place of dry-erase or bulletin boards. Even as gesture recognition is perfected, there's still no inherent reason why it will be better than keyboard, mouse, and touch controls for PCs and laptops; touch and voice may well be the best input methods for mobile devices and tablets.

The future of gesture is embedded, not stand-alone: Leap Motion announced partnerships with Asus in January and HP in April to embed its gesture-recognition technology in some of their laptops. This is how most consumers will encounter PC gesture controls. That will provide more distribution for Leap, but it doesn't mean anyone will use it. In the control panel of my Windows 7 laptop, there are 54 items, with Leap being one of them. Many of those 54 options reference features I will never use.

Leap's awaiting its killer app. Xbox needed Halo. The iPhone needed Shazam and Angry Birds. Crowdfunding needed Kickstarter. The printing press needed the Bible. Broadcast television needed "I Love Lucy," and cable television needed CNN (and the Persian Gulf War). Every technology and medium needs killer apps to demonstrate the value to mass markets. Even if the killer app for gesture inputs and Leap isn't clear yet, it may exist or surface later on.

Leap deserves kudos for delivering a product that at least gives users a taste for what gesture can do. The biggest danger for Leap today is that it's just as easy to wave hello as it is goodbye.