IT BEGAN in 2004 with an idealistic promise by the mayor of San Francisco, Gavin Newsom: "We will not stop until every San Franciscan has access to free wireless-internet service." But stop they did, when a privately funded municipal-scale network backed by Google, with EarthLink Networks as a partner, proved impractical. Nine years later a tiny fraction of the originally planned free network has come to life with Google's announcement of a donation to blanket 31 of the city's parks with Wi-Fi.

For a brief heyday from roughly 2005 to 2007, dozens of cities issued calls for proposals that were answered by EarthLink (without Google, except in San Francisco and one other place), MetroFi, and many others. This newspaper posed the question in March 2006, "Wi-Pie in the Sky?" (Answer: yes.) These firms promised, often at no cost to the city or county in question, to shroud tens to hundreds of square miles with Wi-Fi service. Many networks were touted as designed to reach homeowners and apartment dwellers with the addition of an indoor signal booster. In some cases, as in San Francisco, a tier or limited free usage was planned or offered alongside premium paid tiers. When launched, networks promised bandwidth of a few megabits per second, which was higher than most DSL lines at the time and comparable to many cable modem systems.

In hindsight, these efforts were doomed to failure, an expression of unwavering but unwarranted optimism by the several early metropolitan-scale Wi-Fi-router-makers who vied for hundreds of millions of dollars in equipment contracts paired with the naiveté of early network deployers. Tests showed promise, but deployment revealed severe deficiencies. The density of equipment necessary to make seamless and ubiquitous Wi-Fi work outdoors in an average city was prohibitively expensive with the technology available at the time. Our article in 2006 concluded thus: "Whether service providers will be able to meet the required technical standards and still make a profit will soon become clear." And it did, but only after oodles of cash had been spent.

San Francisco accepted a bid by Google and EarthLink in early 2006. It was dead by late 2007. EarthLink bet big on city-wide Wi-Fi because its only viable business, dial-up-modem internet access, had plummeted with the spread of DSL and cable modems. Several regulatory and court decisions had left most of America with wiring to the house owned exclusively by incumbents. Telecoms were not required to give other firms non-discriminatory access. Nor were they obliged to offer the same wholesale pricing as their in-house internet divisions. The penalties by regulators for tardy or faulty installations, if levied at all, came late and were meagre. And in any case, the Supreme Court ruled meant that cable firms did not have to provide access to competitors.

By 2008 EarthLink and others like it, including groups within AT&T and Motorola, pulled the plug on nearly every network under construction in North America. They also cancelled those on the drawing board. Portland, Oregon, had the ignominy of having to pay tens of thousands of dollars out of city coffers to remove abandoned antennas left by its partner. Many in Europe and Asia suffered the same fate, but there was less interest outside of America, as 3G mobile internet had been deployed much earlier.

Some of the first wave of companies, and a fresh batch including Meraki and Ruckus Wireless, pushed mesh networking as a solution. In a mesh network, every wireless router can relay data to any other within range. The data hop from one router to the next until reaching one connected to the internet. This decreases costs substantially. In 2008 Meraki announced a revival of the city-wide network idea in San Francisco, but without any municipal participation. While it grew for a few years to transmit terabytes of data a day at its height, the "Free the Net" network quietly disappeared a couple of years ago. Networking giant Cisco acquired Meraki in November 2012.

While large-scale Wi-Fi sputtered, mobile carriers in America and Canada appear were prodded into action. Together with their wired divisions they vociferously denounced any public money assigned to private city-wide networks, even lobbying for laws banning it. By 2008, however, 3G networks were everywhere, and by 2012 3G+ followed across the full footprint of AT&T and T-Mobile (albeit in fits and starts). Verizon lagged, then leapt forward with 4G LTE. Carriers now compete for the broadest LTE rollout, which provides data rates as fast as cable modems, though at a high price.

Wander the streets of San Francisco today, or any city in the developed world, for that matter, and you find it hard not to stumble on a free network. Every cafe, convention centre and airport has Wi-Fi, as do academic campuses, many city centres and retail districts. Telecoms firms like AT&T supplement mobile spectrum with Wi-Fi hotspots and zones, and most of the Wi-Fi equipment firms that survived the metro-network days sell hardware both for corporate networks and for outdoor deployment by carriers.

Three large-scale ventures did emerge from the ruins of the city-wide Wi-Fi implosion. In Minneapolis, the private firm USI Wireless operates a Wi-Fi network across the entire city, the only large American municipality with such an offering. Its success proves a rule: the city signed a 10-year, $12.5m contract with the firm that started being paid out at 10% each year long before the city could use the network's services. USI was a relative latecomer, which let it adopt newer and niftier hardware, but also just early enough to complete its network and acquire most of its customers before Minneapolis had received all the benefits of high-speed mobile internet service.

Across the Northeast, Cablevision has installed many thousands of Wi-Fi routers, providing dense and free coverage in parts of towns in its service area, but offers access only to its cable subscribers and those of other cable firms. And the mid-sized town of Mountain View, California, has an extensive, free network run by Google, which has its headquarters there.

Google's generous effort for San Francisco is rather modest. The internet giant is providing $600,000 to cover the cost of installation and two years' operation handled by a subcontractor, a figure that would have been enough to cover half a square mile with service back in 2006. Even so, visitors to the parks and recreation centres that Google will equip might be excused if, as they wander with eyes locked onto their mobile devices, they sceptically click cancel when a network named "Google Free WiFi" appears on their displays.