It was back in 2011 when Richa Kar realized that, when it comes to buying lingerie, Indian women were under supported. When she was 30, it dawned on her that many such retailers didn't stock a wide enough range of sizes, and that in some parts of the country such stores were hard to find. At the same time, she found that many Indian women felt uncomfortable buying underwear from a shop, and that they had a lack of awareness of the different types of such products available to them. Ms Kar, who four years ago was helping a global lingerie retailer develop an Indian marketing strategy, decided that the solution to all these issues would be to open an India-wide online lingerie shop. So quitting her then day job, she did just that, launching her website Zivame in August 2011. Speaking at a panel discussion on the Indian-start up scene organised in Bangalore by BBC TV show Talking Business, Ms Kar says: "Usually retailers stock only fast-moving sizes, while tail ends of sizes remain under-served. Image caption Zivame's website has now been up and running for almost four years. "And some sales personnel only push sales, rather than providing consultation on the right fit and style. That is why I conceptualized an online lingerie store."Since its launch, Zivame's revenues have more than tripled each year, helped by the growing number of Indians shopping online. The Bangalore-based company today employs 250 people, and has raised more than $15m (£10m) from large Indian investors. In addition to lingerie, it now sells swimwear and pajamas. Ms Kar is just one example of the many hundreds of young Indians who are increasingly taking on the challenge of setting up their own businesses. Led by new entrants into the country's technology sector, this is transforming India into the world's fourth-largest hub for start-ups, according to the Ministry of Finance's Economy Survey 2014-15. And thanks to the vast scale of India's marketplace - the country is expected to overtake China as the world's most populous country from 2028 - overseas investors are increasingly showing an interest. This is especially true in the online space, where 240 million Indians now have internet access, according to research group IMRB International. IMRB says this is the third highest in the world after China and the US, which India is expected to overtake this year.