How a Startup Is Helping Retailers by Using Digital Tests in Physical Spaces An NYC startup applies A/B testing -- common in the digital space -- to convert foot traffic to sales in brick-and-mortar stores.

Y Combinator's Kat Mañalac remembers well the day last year when she met Prayas Analytics founders Pranshu Maheshwari and Yash Kothari. Mañalac was visiting the Wharton School in Philadelphia as part of YC's spring campus tour, where the accelerator scouts investment opportunities and offers winners a flat $120,000 for a 7 percent stake in their business.

"They had handmade T-shirts on," she recalls. "Yash's shirt said "I [heart] YC' and Pranshu's said "I [heart] Traction.'"

Those shirts got to the heart of the duo's pitch, functioning as a live A/B test, a common practice in the digital space in which users are served various search outcomes from identical queries, website designs and calls to action in order to see which generate the most sales. For the record, Mañalac preferred Kothari's shirt. She also liked the idea for Prayas Analytics, which led to YC's investment in the two college seniors, who have since graduated and set up shop in New York City.