IDC predicts Internet of Things will be an $800 billion market by the end of this year.

Global IoT spending is forecast to reach $1.4 trillion by 2021, predicts IDC, up from $800 billion in 2017.

According to the research firm, the big spenders on IoT this year will be manufacturing, which will splash $183 billion, while transportation and utilities will spend $85 billion and $66 billion respectively. Cross-industry IoT spending, which covers use cases common to all industries – such as connected cars and smart buildings – will reach $86 billion, IDC said, while consumer IoT spending is expected to reach $62 billion.

"The discussion about IoT has shifted away from the number of devices connected," claimed Carrie MacGillivray, vice president, Internet of Things and Mobility at IDC, in a research note last week. "The true value of IoT is being realised when the software and services come together to enable the capture, interpretation, and action on data produced by IoT endpoints."

In terms of compound annual growth rates (CAGR), the biggest risers over the five years to 2021 are expected to be the insurance sector, which will grow by 20.2%, followed by consumer at 19.4% and cross-industry at 17.6%.

From a use case point of view, IDC said manufacturing operations is expected to be the biggest, attracting investment of $105 billion this year. Smart grid technology, such as utility meters, is expected to account for $56 billion, while smart building technology will account for $40 billion.

In the five years to 2021, IDC expects airport facilities automation to be the use case that sees the largest CAGR, increasing by 33.4%. Electric vehicle charging will grow by 21.1%, and in-store contextual marketing will grow by 20.2%.