ATLANTA — Steve Parker, sitting in the atrium at Hartsfield-Jackson Atlanta International Airport last week, was about to dig into his bag for a hot spot device when he noticed a poster nearby.

“Wi-Fi Before You Fly. Now Free,” it announced.

Saving a speck of time and trouble, Parker tapped directly into the service offered by the airport, where fliers without their own Wi-Fi alternative had paid $4.95 per day.

Minutes later, Parker, a contractor in the military industry from Rehoboth Beach, Delaware, declared the newly unveiled system “perfect — easy and painless.”

Unlimited Digital Access. $1 for 4 weeks.

“All airports should do this,” he said.

Not all do, but the roll call of free arrangements — entirely at some airports, in combination with premium-paid levels at others — is growing, both domestically and abroad. As airlines tack on fees for ever-fading courtesies, from checked baggage to advance seat selection, airports are headed in the opposite philosophical direction when it comes to Wi-Fi.

Of the nation’s 30 busiest airports, 12 offer all-free Internet, up from nine in 2007, according to Boingo Wireless, a leading provider of airport wireless services. A dozen others opt for a tiered plan, with some free access. The shift is also playing out at smaller locations, where the financial and operational challenges are less daunting.

For much of society, free Wi-Fi has evolved into a something of a right, and the trend at airports is to treat it as an amenity no different from water fountains, trams and Muzak.

Hartsfield-Jackson’s general manager, Miguel Southwell, says an airport’s purpose extends beyond transporting sky-minded passengers to “being a catalyst for economic development.” A pleasant experience for travelers, which can include free Wi-Fi, could spawn fresh or expanded businesses.

“We want to exceed customer expectations,” Southwell said.

The fee-based format generated waves of dissatisfaction. Consumer surveys found that a third of Hartsfield-Jackson’s travelers identified the absence of free Wi-Fi as their primary complaint by a wide margin.

The switch comes at a steep initial price. Gone is $1.5 million in annual revenue from the pay service, along with $5.6 million appropriated by the Atlanta City Council to cover the design, equipment and installation.

Mayor Kasim Reed, who trumpeted the changeover at a news conference staged within a few paces of Parker and others hunched over their portable computers, voiced confidence that some lost revenue would be recouped through more spending at airport establishments.