Earlier this week Google announced that their Map Maker product was being launching in the UK. Map Maker lets users make changes to Google's popular Maps service, helping Google improve their map data with the assistance of the crowd. The product has been around since 2008, originally available only in countries that didn't really have any map data, and later expanding into countries that already had good coverage but could be improved with additional information.
Map Maker works in a similar way to the OpenStreetMap project (which started around 2006) in that they both let people edit the details on their respective map, but there are some noticeable differences between Map Maker and OpenStreetMap.
(I've been using and contributing to OpenStreetMap since the early days of the project, so I'm going to be biased towards it, but I think both Map Maker and OSM have things going for them.)
As probably the most widely used map in the world, Google Maps has a large number of people looking at their maps for local information. Most of them have local knowledge about an area, and a very small percentage of them may want to help improve their local maps for their own benefit and for others. On the other hand, OpenStreetMap's user base is much smaller (though has been growing quickly for years), and for the most part consists only of those people who want to help build the maps. Both Google Maps and OpenStreetMap can be embedded into other websites, but the end users of those sites are unlikely to care about making updates to the map, it's only people who use Google Maps or OpenStreetMap directly who'd do that.
Editing a place in Google Maps means that your information is currently going to be seen by many more casual users than if you were to edit OpenStreetMap, but with the inclusion of OpenStreetMap data in many other projects (like Apple Maps, MapQuest, MapBox) there are also massive advantages to making sure the information is up to date in there too. If you're promoting your business, you should definitely make sure to add it to OpenStreetMap as well.
With any service where you're giving lots of unknown people a chance to share information that is visible to the public, you're likely to get people vandalising that information, whether it be accidentally, for a bit of fun, or for any other reason. Google Map Maker has a moderation feature which stops all edits being added to the map automatically, and only lets them through after they've been vetted by trusted users. OpenStreetMap doesn't have up-front moderation, but has tools in place to let users keep an eye on areas they know. Both approaches have their merits and disadvantages.
Editing interface and user experience
The interface to Google Map Maker is designed to be easy to access when you're looking at a map (look out for the 'edit in Map Maker' link in the bottom right corner of the map) and makes it as simple as possible for people to add new places, edit existing ones (accurate business information is what Google is hoping for here), add roads, and review other peoples' edits. The interface is perhaps a bit more intuitive than OpenStreetMap might be for a new user at the moment, but some of that is because it has to cater for less technical users. OpenStreetMap is making efforts to improve this initial user experience too though, with improvements to the website and in particular the development of the new iD editor which aims to make editing simpler.
Using the maps and map data
Both Google Maps and OpenStreetMap can be embedded into your own website to show the location of your business, or to overlay whatever other information you'd like to display. With Google Maps you can change some of the styling, and choose to hide some of the information (with some technical know how), but you never have full control over what you're showing. If you want to show where your business is without also promoting your competitors, you're out of luck. With OpenStreetMap however, you can have complete control over what you show and what you don't, especially if you use a service like MapBox to customise your maps, or download any one of a number of opensource tools to build your maps exactly as you like.
Any information that you add into Google is owned by Google, and shown on a service that could in theory be withdrawn at any time (see Google Reader). Any information you add into OpenStreetMap is licensed freely for people to reuse as they like, so if you're adding information about your business into OSM, it's got the potential to be promoted much more widely than if it's just in Google Maps. The information in OSM will always be available to use as it's not dependent on any one commercial entity.
So, which should I use?
Personally, I'm happy to add some information into Google Maps, such as if I'm helping to promote a local business, but I'll also make sure that information is mirrored (and bettered) in OpenStreetMap. If I'm going to add in any sizable chunk of information, I'll just add that into OpenStreetMap as adding it into Google would be doing work for them for free without being able to reuse that information myself.
As an example, the maps below show Foxdale in the Isle of Man, in both Google Maps and OpenStreetMap. I help out with the online bits for some self-catering farm cottages in the village, so I've added their location and a bit of detail around the farm into Google Maps, but if you look in OpenStreetMap you'll see a lot more detail for the whole village as well.
Foxdale looks a bit bare in Google Maps, but check it out in OpenStreetMap:
If this post has inspired you to add your business information into OpenStreetMap, check out this quick guide to adding your first point.