My most-trusted source for Facebook stats, SocialBakers, states that Top 5 African Cities by Facebook Users are:

The list above was compiled from SocialBakers’ Global Top 120 Cities.
At first glance, I thought this was interesting. However, common sense dictated that something was amiss with the list of cities in Graph 1, thus it need to be validated. The exercise started with ranking of Top 5 African Countries on Facebook, using the same source, SocialBakers. The result deepened my curiosity, as shown in Graph 2:

Given rapidly growing mobile phone access on the African continent that far outstrips landline access and thus influences Internet access, the Top 5 Countries by Number of Mobile Phones is as follows:

According to StatWorld’s 2009 report, the ratio of number of mobile phones to landlines in Africa is 44:1. DRC virtually has no landlines with a ratio of 223:1.
The last step was to look at Top 5 African Metropolitan Cities by population size. This was to see if SocialBakers’ Top 5 Cities on Facebook appear at all in the list, and none of them do:

The only caution relating to Graph 4 is that the population sizes come from Census years that are far apart in some cases – Lagos (2006), Cairo (2006), Kinshasa (1998), Johannesburg (2007) and Khartoum (1993). The worrisome population sizes would be for Kinshasa and Khartoum, and I am not qualified to venture into any speculation about what could have happened to these two metropolises ever since. Being that as it may, these are the official numbers and I am going to work with them as they are.
My analysis shows that the closest stats are found in Graphs 2 and 3, albeit with a slightly different ranking order. This did not concern me at all given the different metrics that were used. Graph 4 has 3 of the 5 countries found in Graphs 2 and 3. Graph 1 is the odd man out, and this confirmed my common sense that something was indeed amiss.
The analysis above lead me to believe that SocialBakers’ ranking of African cities on Facebook is not accurate. But this has not affected the trust I have in this source as the best for Facebook stats. The only explanation could be that this metric is still in Beta version. I have sent SocialBakers developers an email pointing this out. Unfortunately, I had not received feedback by the time this blog post “went to press”. I subsequently received their response, and the body of the email is here below.

I am waiting with anticipation for ultimate publishing of accurate report (hopefully not for too long). This will add another feather in the hat of social media’s power of analytics.
Key insight: Do not use only one source for online stats, where possible. The more reputable the source, the better. At the same time, beware of analysis paralysis. My rule of thumb is minimum 2 and maximum 5 sources, depending on the objective of the analysis.
Do you use a different rule of thumb when performing online analytics? Share your experience with me by leaving your comment below.
- Nuffdotty – where thoughts on the subject of education, mostly relating to South Africa, are shared
- Diski4Life – a blog about development of South African soccer post World Cup 2010