Factory's CEO said that he bought employees $3,000 Eight Sleep mattress covers because he was "optimizing for output." Eight Sleep Factory CEO Matan Grinberg said he bought 30 employees $3,000 mattress covers so they could be "sharper." Grinberg said he bought products from Eight Sleep. The smart covers use liquid tubing to cool and heat a bed. "I want to make sure everyone is squeezing out every ounce of brain power they have," he told Business Insider. How much would you pay to help your ...