Yeah, of course it's limited, and there might be regional biases toward publishing your true location, but I think as @sco said, it does give a statistically sound representative image.
Also, since the active user number is much lower, I can imagine that the representative figure here is higher than 10%. I think active (or real) users probably have a higher tendency to publish their location. There are a lot of account creations for the sake of registering names early (dot com rush style) or for whatever other reasons other than actively participating in the social media.
From a statistical point of view, 10% should give a very well representative picture.
Yeah, of course it's limited, and there might be regional biases toward publishing your true location, but I think as @sco said, it does give a statistically sound representative image.
Also, since the active user number is much lower, I can imagine that the representative figure here is higher than 10%. I think active (or real) users probably have a higher tendency to publish their location. There are a lot of account creations for the sake of registering names early (dot com rush style) or for whatever other reasons other than actively participating in the social media.