Just received this deal via email though doesn't say which state or location. Possibly targeted.
50% OFF PARKING
Valid for Night, Weekend & Hourly Parking rates (excluding Early Bird) when you book online with Secure-a-Spot.
Not valid for Early Bird Parking or any product at SW1, Office Park or Darling & Co Car Parks.
A booking fee of $1.00 will apply to each Secure-a-Spot transaction.