PayPal saw the use of its buy-now-pay-later payment service soar on Black Friday. In an interview with CNBC's Jim Cramer, PayPal CEO Dan Schulman said that the volume of sales on its Pay in 4 service jumped by 400% this Black Friday, compared with the previous year. "We did some 750,000 transactions alone in one day on Black Friday," he told the outlet, describing its payment instalment service as "one of the stars" of the holiday season.