Just to let you know Virgin puts its paxing crew in the exit rows.
Obviously they are the best people on the aircraft as passengers to be in the exit row.
Also Virgin do not allow online, mobile or kiosk check-in to exit rows. All guests that have booked the exit row are checked and asked the required question on whether they are fit and willing and it also allows the agent at check in to look at them and ensure there are no issues (eg. broken arm/leg, requiring oxygen during flight, non-English speaker etc etc etc).
I have kicked many people out of the exit row, especially on landing after we find they have had a whole litre of duty free alcohol during the flight. Don't care if people pay for it, they need to be with it and able to operate the exit. For those interested in a prepared evacuation all occupants of the exit row are re-briefed and it is checked each of them are still willing to sit there and operate the exit if required.