The article introduces a new way to understand what people buy in developing countries. By looking at how much money different groups of people have, we can predict what products they will want. This method is better than just looking at the average income of a country. The researchers found that knowing the income distribution helps companies figure out what makes people buy certain brands. By combining income data with other information like prices and marketing, we can see what factors influence people's buying choices, even in countries that are hard to study.