I think that means that the high sales are Pulp related, rather than being linked to the early announcement.
As evidenced by the seemingly slow sales for Saturday / Sunday day tickets.
Parking right outside the entrance is a big plus, but honestly, the guaranteed pitch, the space, the bar, the pizza & coffee, the showers, the clean plentiful loos...all add up to a very leisurely experience even if you have to wander over from PGA! If I was arriving Thursday and wanted to know I had a spot reserved, I'd do it in a heartbeat. Basically, the parking is the cherry on top.