Netflix reportedly made the decision following the directive of the European Commissioner. He suggested watching standard video instead of HD video to reduce the Internet consumption at this time.
Standard video consumption consumes 1GB of data in one hour, while HD video consumes 3GB of data. Accordingly, Netflix has also decided to reduce the quality of its streaming service.
Some of Netflix's programs even feature Ultra HD. As Netflix lowers the video quality, Internet data consumption will be reduced by 25%.