Sitanshu Sheth and Shardul Sheth, 

Agrostar is a mobile-commerce platform for farmers to procure seeds, crop nutrients, even tractors, at their doorstep. The Sheths have signed up 400,000 farmers, with a quarter converted to customers. “Farmers like AgroStar for quality and reliability, not discounts. That’s how early it is in this market,” says T.C. Meenakshisundaram, managing director of IDG Ventures, which led a $4 million round in 2015. He estimates the farm-inputs market at $45 billion.