The book aims at an important although very challenging topic -- the subtitle is "how to create extraordinary products for tomorrow's customers".
What it delivers is a collection of pointers on how to do field research on product usage, and some observations on some aspects of asian and african everyday culture that are surprising to someone viewing it from the perspective of a western culture.
The book does provide some interesting observations on what is important to consumers with very limited means, and how they organize consumption.
One pitfall the book highlights is products for the elderly, the illiterate and the poor. The observation is that again and again, these groups do not "rationally" choose a product designed for them, be it a phone with extra large buttons and large, simplified graphics for the elderly, an off-brand phone supporting the local language, or the Tata Nano, "the cheapest car". Basically, few want to embrace or signal belonging to a group that needs a special, compromised product.
I think another factor is at play in mispredicting preferences of these target segments: typically, those doing the extrapolation do not sufficiently adapt their frame of reference. That is, a marketing executive might ask themselves, "if I lived on $5/day, would I rather eat well and have an off-brand phone, or cut corners on my meals but have a basic Nokia?" To the exec, the answer is a resounding "eat well", since the distinction between an off-brand and low-end branded phone seem minor (neither is that desirable, to him) and he would imagine money is better directed to trying to restore current economic status. So, the exec might imagine the less affluent basically as more utilitarian and driven to gaining affluence.
A more accurate model, however, is to view a person as typically in balance in terms of earning and meeting their needs. A low-end branded phone has positive signaling value, and thus is surprisingly desirable. Similarly, Symphony, an upmarket air cooler brand in India has had dramatic success selling $200 branded "fan plus wet sponge" devices to those for whom an air conditioner is impractical or unaffordable.
Another interesting observation is that societies can adapt to consume mass-market technology of the affluent countries. For example, cell phones and charging stations can be shared in a village, and time credits can be used to transfer money (by communicating the pin unlocking additional money credits).
The importance of that is that sometimes an existing product can be made successful in a radically different market by altering the distribution channel rather than the (mass-produced) product.
The author also points out examples of unusual signaling -- such as fake braces to signal the ability to afford orthodontics (as well as, perhaps, the promise of straight teeth in the future); the author also marvels as how smoothly running a subway station in Tokyo is, attributing it to greater importance placed in the culture on not inconveniencing others.
All in all, I don't recommend this book with an ambitious subtitle, although it did prompt a few interesting insights -- the most important one perhaps about some dynamics that drive success of branded goods in low end markets, and common pitfalls in thinking about what those markets would want.