Though I use it, I'm unconvinced about the medium term future of Foursquare (though not location based networking in general) as I explained in a previous post.
However, these RJ Metrics stats on Foursquare and its smaller rival Gowalla will be useful for anyone looking into the services in any detail.
RJ Metrics is providing a running count over at startupdata.rjmetrics.com (hat tip Nick Burcher), which shows that on of the morning of 15 August, Foursquare was on 2.7 million users compared to 402k odd for Gowalla - and that's a global figure.
Comparing active users - Twitter vs Foursquare
How many of those 2.7 million users check in regularly? Foursquare itself says that there are one million check-ins a day...which is of course not the same as saying that there are one million human beings checking-in every day.
To take the Forrester stats from last month: They showed that 2% of online Americans 'rarely' use location based networks, 1% use them weekly or less, and 1% use them once a week. As a result, it's reasonable to assume that Foursquare's active user base is at most 50%. And anecdotal evidence suggests that figure is far lower. This then gives us a maximum active global user base of 1.4 million.
And what about Twitter? Earlier this year RJ Metrics found that 83% of accounts were dormant every month. Based on the latest Comscore figures of 93 million users, that would give us a minimum active Twitter global user base of around 14 million.
The future of check-ins - event rather than location based?
Finally, something we linked back to in the last Rabbit Feed (our weekly newsletter over at Rabbit) - Mashable recently asked whether the future of social check-ins was event / entertainment based. The tech website profiled a number of new services including Miso, Get Glue, and (not available yet on the UK iTunes store) Philo.
Last week CNET said that Facebook may well also be looking at integrating an events function into its forthcoming geo-location service, following the acquisition of entertainment check-in service Hot Potato.
As an aside, one new location based network I have been watching with interest is Snikkr. Claiming to fuse social networking, productivity and location based services, Snikkr appears to position itself first and foremost as a utility.
No badge collecting, is involved and it integrates with Twitter and also Yahoo!'s Fire Eagle (in itself an interesting service). Snikkr also has a TrackMe function where for a period of time you can allow selected friends to see where you are - useful if you are with a group visiting a certain location.