Take context from the input text and decide on the accurate relationship between 'hotels' and 'Booking.com' from the options provided.
Options: member of, operator, platform, product/material produced

The commission rates paid by hotels in Australia had long been lower than the global average of 20 per cent to 25 per cent because Wotif had charged less than Booking.com owner Priceline and Expedia did overseas.
operator