Social media technologies and services have empowered individuals and organisations by revolutionalising the way people communicate, socialise and conduct business. Two examples of social media services are Facebook and Twitter. Many organisations have been quick to realise the potential benefits of social media and have adopted social media marketing practices. Social media analytics are conducted by organisations to analyse social media data in order to determine the influence of their marketing activities as well as those of their competitors. The discussion in this paper stresses the widespread adoption of social media on the African continent and the usage of social media by marketing departments in organisations. An assessment is conducted on the usefulness of online social media analytics services, and finally, the paper identifies some challenges and opportunities for social network data analytics.