A Facebook director has dismissed claims that the social network ditched last year’s big redesign because it was bad for ad revenues. Those claims came from Dustin Curtis, a UX designer and writer who owns the publishing platform Svbtle. In a blog post on Friday, Curtis cited several sources saying Facebook found that testers of the redesigned News Feed were spending less time in user profiles and event pages. “The new News Feed was performing too well,” says Curtis. “This change in user behavior led to fewer advertisement impressions, which led, ultimately, to less revenue.” However, according to Facebook’s product design director Julie Zhuo, Curtis’ sources are incorrect. In a post on her blog, Zhuo explains that the reason for ditching the new design was poor performance on older and less-expensive computers. “The design we tested a year ago wasn’t better for the majority of people,” says Zhuo.