I booked a hotel via booking.com in Sweden and the hotel had mistakenly cancelled my reservation. I called the booking.com helpline and they took immediate action, called the hotel, volunteered to take care of finding an alternative. It was the first time that I thought it is actually helpful to book via a page like booking.com because had I been left to myself in the hotel I would have had to deal with them myself and they werent very forthcoming at all (and tried to blame the whole situation on me).