The mass merchandiser channel has received a much-need boost from Harry Potter and the Cursed Child: Parts 1 & 2.

According to Nielsen BookScan, first week sales of the script book, which was released by Scholastic nationwide on July 31, were 2.5 million. (BookScan estimates it covers about 80% of print book sales; Scholastic recently reported that Cursed Child has sold 3.3 million copies since its release.)

While sales through book clubs and retailers enjoyed a solid jump in sales in the week, it was mass merchants who really benefited from the release of the book. The channel, which includes major chains such as Walmart, accounted for 33% of the first week sales of the book, with units hitting just shy of 848,000.

That 33% share of is much higher than the slice of a book's sales that mass merchandisers typically account for. For the week ended Aug.7, for example, the mass merchandiser channel only represented 17% of all unit sales for the week.

In fact, the channel has been struggling with book sales for all of 2016. Even with the spark from Cursed Child, which led to a 40% increase in sales for the week, unit sales in the mass merchandiser channel were down 4% through Aug. 7 compared to the same period in 2015.