Sure there’re alot of factors that help sell a game, but what i’m saying is that if this game wasn’t associated with Harry Potter it wouldn’t have had the same success imo. So In this case it helped alot.
Spider man is a good example. It sold well during the act days even if it had alot quality issues. Also it’s hard to compare the gaming market in those days with today, you can’t have a clare cut comparison like that due to alot of factors in play.
The power of a brand name can carry a product even if said product is trash. See Pokemon.