It's not. "Highest number of sales" can mean either "highest revenue" or "most units sold". The author ran with "Nikon Sold More Z9 Cameras than..." when that's

It's not. "Highest number of sales" can mean either "highest revenue" or "most units sold". The author ran with "Nikon Sold More Z9 Cameras than..." when that's 1. not what management said and 2. there's good reason to believe that they're referring to revenue when reading the statement in the context of the release.