Although only about one in 20 of the world's first two billion mobile subscribers live in India, as many as one in every four of the next billion subscribers will be an Indian, a report by the Boston Consulting Group said.

The report focuses on a distinct group of consumers -- the next billion -- whose potential to become profitable customers has been greatly underestimated.

Based on extensive primary research, the BCG study has estimated that around 91 million households in India belong to this next billion segment.

These households have been identified based on a combination of factors including household savings, discretionary expenditure, ownership of basic consumer durables and banking relationships, the report added.

Categorised by income, this segment sits just above the poorest of the poor and just below consumers who are already targeted by most companies. In India, income of the urban next billion household varies between Rs 60,000 and Rs 180,000 per annum.

In rural areas, the floor is lower at Rs 40,000 per annum reflecting the lower cost of living. There are 18 million households in India that lie above the next billion segment and 95 million households that are below the next billion.

BCG has surveyed over 15,000 next billion customers and conducted several focus group discussions and in-depth interviews across India, Brazil and China to understand their aspirations, needs and behaviours.

James Abraham, a partner and director in BCG's New Delhi office and a co-author of the report, said: "The next billion will be different from the first two. For the next billion, the mobile phone can change their lives, improving their economic prospects more significantly than any other tool."