One-third of Internet of Things (IoT) projects fail, and those firms that give up do so mainly for cost reasons.

New research by Cisco shows only 26 percent of firms regard their IoT projects as completely successful, and fully one-third of projects were considered unsuccessful.

In a separate study, GlobalData found that the companies that give up on their IoT projects do so because they are too expensive to implement (41 percent), and because their priorities shift (23 percent).

Another 21 percent found they are too costly to maintain.

The GlobalData and Cisco surveys each asked more than 1,000 users about their IoT investments.

Replies show that firms are more willing to try out the technology. However, this also led to more projects being abandoned later in the project lifecycle.

GlobalData and Cisco separately found that firms kill about 60 percent of their IoT projects in the investigation phase.

But more actual projects are getting the green light, and entering production, as evidenced by the rising number of IoT connections reported by telcos such as AT&T, Verizon and Vodafone.

AT&T reports quarter on quarter growth rates of 65 percent, while Vodafone claims an annual 42 percent growth rate, and Verizon claims to be on track to add $1bn from IoT sales.

Even so, some customers pulled the plug after going live.

GlobalData found that six percent abandoned their projects in the deployment phase and another six percent in post-deployment phases, citing implementation and maintenance costs reasons, as well as changed priorities.

Cisco’s survey found that human factors such as cooperation between the IT and business side, a technology-focused corporate culture, and IoT expertise, whether from internal or external sources, are key success factors.