Last week, Craigslist added OpenStreetMap data to its apartment listings, providing some much-needed geographic context to its site. Craigslist is notoriously conservative with respect to its design and user interface, but the site appears to have capitulated to pressure brought about by the likes of PadMapper and others that are desperately trying to improve upon Craigslist’s massive classified ads service.

With the addition of OpenStreetMap to one of the most heavily-trafficked sites in the United States, it appears that crowdsourced geographic data has arrived. Craigslist’s adoption, of course, comes just months after Foursquare, Wikipedia, and Apple all joined the OpenStreetMap party.

Many of those sites likely switched away from Google Maps due to the company's increased API usage fees announced last year, which then dropped by 75 percent as of June 2012. Still, as a result, the UK-based foundation behind OpenStreetMap says that as of July 2012, the group now has 650,000 registered users on the site. It's hitting new heights with the amount of map data being generated on a global scale daily.

"Google Maps offers bells and whistles that OpenStreetMap doesn't, such as street level data [and] more updates to imagery," wrote Caitlin Dempsey, the editor of GISLounge.com, in an e-mail sent to Ars. "Most people probably default to using Google Maps because that's what's most popular at the moment. Having popular companies such as Apple, Craigslist, and Foursquare switch to non-Google mapping options is certainly opening up users to a broader view of what choices there are out there."

Not surprisingly, OpenStreetMap's creators applauded Craigslist's move, too.

"I think it's another major website making a great decision," said Steve Coast, the founder of OpenStreetMap. He told Ars that he was unaware of Craigslist’s move until being sent a link to other media coverage on Tuesday.

Craigslist, like FourSquare, Apple, and other companies ranging from Royal Mail in the United Kingdom to RTL Luxembourg, do not have to get permission from OpenStreetMap to use the service. The data, after all, is free to use.

Businesses more comfortable with OpenStreetMap

Mapping industry analysts say that the increased number of major commercial operations switching to OpenStreetMap suggests the group may be much more disruptive than when it originally began in 2004.

"Having a business based on map-based data is not a long-term value proposition," said Thilo Koslowski, an analyst with Gartner Research.

"It becomes relatively easy to have people collect information for free. That’s exactly what’s happening now. Businesses are comfortable with using companies like OSM to replace commercial products that they were using before. That demonstrates that these types of crowdsourced services are reliable enough and that companies feel comfortable enough to use companies like OSM, which is great."

Going forward, ordinary Internet users may become increasingly aware of OpenStreetMap, just as they are with Wikipedia, if many of their favorite sites and services begin switching to the free alternative.

"I think the consumer cares whether the map is good and whether it's useful for what they want to use it for," Coast added.

"The fact that there are so many parks, buildings, all the things that you don't find in other maps—that's better for the consumer. Do they care about the name? Not really. Do they care about the experience? Absolutely."

Developing world can leapfrog ahead with open-data maps

Of course, given that OpenStreetMap remains a crowdsourced operation which relies on mapping parties and geo-enthused participants, the group is continuing to make headway into rural parts and under-traveled parts of the world. Coast added that the group has found, based on its own experience, that for OpenStreetMap to reach the level of a proprietary map, there needs to be about 15 people per square mile helping to input data.

But experts point out that during a crisis, the OpenStreetMap community can and has come together to develop detailed geodata for parts of the world that historically have not had very accurate maps, like during the Iraq war, or following the 2010 earthquake in Haiti.

"For lesser traveled areas, the maps still might be needing some more information," Kevin Hamlin, an analyst with IHS Global Insight, wrote in an e-mail sent to Ars. "The Haiti example again applies, as the maps they had before the earthquake were fairly rudimentary with just main streets and not a lot of detail, but when there became a need, it became populated quite quickly."