Uber Technologies Inc. noted that its UberX drivers, about 12,000 in the Philadelphia region, typically keep 80 percent of the revenue from receipts. Uber and Lyft would not discuss their profits, but Uber in particular has tended to subsidize its services in order to attract customers and incentivize drivers. It devoted $2.5 million to beefing up its UberPool service this summer, and covered the difference for drivers when it offered a 40 percent discount to passengers who took UberX to or from certain SEPTA stations in the suburbs. The San Francisco-based company is valued at up to $68 billion, but in August Bloomberg reported Uber had lost $1.27 billion in the first half of this year, and up to $4 billion since it was founded seven years ago.