Beginning in September 2015, bookings by new account holders are charged a service fee amounting to 5-7% of the booking total.
Services booked through a Rover account created prior to the date the fee was implemented will not be subject to the owner service fee. The fee cannot exceed $25/booking. It’s fully refundable should the booking be canceled by either the sitter or the owner prior to the first day of the service, in accordance with your sitter’s cancellation policy. If the booking dates change, the fee will be updated to reflect 5-7% of the new total.
https://support.rover.com/hc/en-us/ar...
BTW, the math on your example doesn't seem to work out, Are you certain that the stay should have priced out at $240 because your net ($211) is 88% and older Rover sitters have been grandfathered into 85% with newer ones (March 2016) at 80% or more? Also, the implied booking fee of $19 is 8% of the total. You probably need to look more closely at the actual invoice and call/write Rover Support for details.