When a South African group launched mobile phones in Nigeria, it made an upper estimate of the market's potential size. Within a few years, the real number of subscribers doubled that topmost guess.
Richard Dowden distils a lifetime's travel in, and study of, the world's most surprising continent into this authoritative but readable survey of Africa today.
With Nigerian mobiles, the prior calculation showed "two profound misunderstandings... first, Africa's ability to pay and second, its desire to communicate".
In this eye-opening book, from Sudan and Somalia to South Africa and Kenya, Africa talks – and Africa trades and buys, ratifying a generally upbeat picture.
From Aids and war to kickbacks and poverty, the downside emerges. But in nomad tents and country clubs alike, hope springs back to confirm that "in its own time and in its own way, Africa will find a better future".