A new report from market analysis firm ABI Research tallies a total of 5.69 million public Wi-Fi hot spots currently deployed worldwide by mobile and fixed-line carriers, as well as third-party service providers.

Looking at a compounded annual growth rate of 11.2%, ABI Research projects that figure will grow to 13.3 million public Wi-Fi hot spots by 2020.

ABI Research Associate Lian Jye Su said the public Wi-Fi hot spot trend is “surprisingly robust. More and more public locations have signed up on a free or freemium [a portmanteau of free and premium]basis.

“This has discouraged the participation of third-party operators in some locales because there is a need for the upgrade of service, coverage and legacy equipment, which is only beneficial for operators with significant economies of scale,” Su said.

The report suggests that a high cost of sale coupled with a low return on investment, has changed the way mobile operators deploy public hot spots in conjunction with residential Wi-Fi.

For example, China Telecom and British Telecom have either slowed down deployments or entered into third-party partnerships, according to the report.

In another business case, U.S.-based Tomizone has moved away from residential broadband Wi-Fi in favor of an emphasis on enterprise customers, particularly in the transportation, retail and hospitality verticals.

In terms of carrier public Wi-Fi hot spot deployment, Oi out of Brazil has put some 1 million public Wi-Fi hot spots in the field, and ETECSA, Togo Telecom and Singtel of Singapore all launched public Wi-Fi hot spot access programs in 2014.

Jake Saunders, VP and practice director of core forecasting for ABI Research, said network operators can also gain a practical advantage through public Wi-Fi hot spot deployments.

“The operators tend to see Wi-Fi hot spots as a method of offloading mobile data traffic, especially in crowded areas,” he said. “Customers do value the experience of high bandwidth connection while on the go, which leads to better customer satisfaction.”