Redmayne said: "We had budgeted for a much lower figure, I had looked at the physical sales of the books, and tried to anticipate what proportion of sales would be digital, and that there was a certain amount of pent-up demand, but it surpassed anything we anticipated." He said post-launch the figure had "settled down" but continued to exceed predictions. "It is still running at a much higher rate than I was anticipating, even for the launch. It is still surpassing anything I've ever seen for e-book sales."

Redmayne said he had put in place an infrastructure and customer services team aimed at meeting customer demand. "Everything that Harry Potter does surpasses expectations. We had planned for something that we just couldn't anticipate."