2016 was a strong year for TASER International, Inc. (NASDAQ:AAXN) stock despite some ups and downs in the last few months. Driving returns for investors is a rapidly growing business, both in Taser and body camera sales. To keep the momentum going, here are a few things investors should watch for in 2017. 

Image source: TASER International. 

Axon and Evidence.com continue to roll

Most people know TASER International as a manufacturer of Tasers and body cameras, but the ecosystem surrounding body cameras is becoming increasingly important. Evidence.com is the company's cloud-based storage solution, which offers unlimited data storage to subscribers and the ability for law enforcement and prosecutors to access footage. New products like on-demand transcripts are also helping to improve the value of the ecosystem. 

TASER is trying to become an indispensable tool for law enforcement and prosecutors, and the more it's ingrained on both sides, the more valuable it becomes. If TASER succeeds in this, it would help drive sales higher, with high-margin Evidence.com and other services attached to many contracts. 

What investors will want to watch is improving functionality of these services and increased backlog. At the end of Q3 2016, the company had $302 million of contracted backlog in the Axon business, and if that grows substantially in 2017, it will certainly help the stock. 

International sales open up

International sales accounted for just $11.3 million in the third quarter, only 15.7% of the company's $71.9 million in sales. And that's just scratching the surface of TASER's potential. 

According to the National Law Enforcement Officers Memorial Fund, there are about 900,000 police officers in the U.S., and based on a United Nations study in 2006, there may be over 20 million worldwide . In theory, international sales could be multiple times higher than U.S. sales, but they're only a fraction of U.S. sales today. Management has invested in expanding sales staff around the world, and growing sales in countries like Australia and the U.K. shows progress, but if momentum takes another step forward in 2017, it could push the stock higher. Look for a regular cadence of contract signings in international markets as a sign that expansion plans are going well. 

New products wow customers

We don't know exactly what TASER International has up its sleeve from a research and development standpoint, but we've got some clues. TASER announced a partnership with Cradlepoint in June 2016 with the goal of connecting and offloading video content from the field wirelessly. This could help decrease the time between when an incident occurs and when the video is viewed by investigators. Again, this ties into improving the Axon and Evidence.com ecosystem by improving the functions they offer to customers. 

We're also seeing further ties between weapons and cameras. Smart weapons can now alert body cameras to start recording, another feature some consumers will like. 

As less lethal weapons and body cameras become more common, the company will learn what customers demand and be able to develop new products to meet those needs. And if new products wow customers in 2017, it'll help push TASER's stock higher.