Regionally, Greater China, North America and Western Europe are driving the use of connected things and the three regions together will represent 67 percent of the overall Internet of Things (IoT) installed base in 2017.

The consumer segment is the largest user of connected things with 5.2 billion units in 2017, which represents 63 percent of the overall number of applications in use. Businesses are on pace to employ 3.1 billion connected things in 2017.

"Aside from automotive systems, the applications that will be most in use by consumers will be smart TVs and digital set-top boxes, while smart electric meters and commercial security cameras will be most in use by businesses," said Peter Middleton, research director at Gartner.

In addition to smart meters, applications tailored to specific industry verticals (including manufacturing field devices, process sensors for electrical generating plants and real-time location devices for healthcare) will drive the use of connected things among businesses through 2017, with 1.6 billion units deployed.

However, from 2018 onwards, cross-industry devices, such as those targeted at smart buildings (including LED lighting, HVAC and physical security systems) will take the lead as connectivity is driven into higher-volume, lower cost devices. In 2020, cross-industry devices will reach 4.4 billion units, while vertical-specific devices will amount to 3.2 billion units.

While consumers purchase more devices, businesses spend more. In 2017, in terms of hardware spending, the use of connected things among businesses will drive $964 billion. Consumer applications will amount to $725 billion in 2017. By 2020, hardware spending from both segments will reach almost $3 trillion.

"IoT services are central to the rise in IoT devices," said Denise Rueb, research director at Gartner. Total IoT services spending (professional, consumer and connectivity services) is on pace to reach $273 billion in 2017.

"Services are dominated by the professional IoT-operational technology category in which providers assist businesses in designing, implementing and operating IoT systems," added Ms. Rueb. "However, connectivity services and consumer services will grow at a faster pace. Consumer IoT services are newer and growing off a small base. Similarly, connectivity services are growing robustly as costs drop, and new applications emerge."