Rebecca by Daphne Du Maurier is, like much of popular fiction, a novel of plot, or action, rather than character. It is part of a literary movement that can be traced from the late 18th century Gothic of Anne Radcliffe through the sensation novels of the 19th century (such as those of M.E. Braddon, Rhoda Broughton, Ouida, etc.) to much of 20th century mass market period romances, in combining an exotic atmosphere, aristocratic protagonists, some element of suspense or horror, hints of the supernatural or mysterious, and a romance plot. When well done (all the authors I’ve named, as well as du Maurier are superbly skilled at plot construction), they provide a reading experience that propels a reader from page to page, building suspense, until that suspense is satisfied by an ending that provides resolution. This reading experience is not conducive to reflection, and many novels in this genre often get by with stereotypical characters and weak prose, relying on velocity and variety of incident to keep the attention of the reader. Thus the experience is essentially a passive one.
I think this greatly depends upon whether you categorise Rebecca as solely popular or not. Some would argue it's a 'popular classic' - as it contains many elements of high literature and aesthetic techniques.
However, if one were to classify Rebecca as a typical 'romance fiction' - this would certainly place it within the 'popular' category of literature. Romances often provide escapism and commonly advocate traditional roles of women at home. If reading the novel as such, it has the potential to encourage a passive reading through a dreamy escapist reading. However, if the reader is prompted to ask questions in the text, and catches on to any sub-texts implied through metaphorical language - than it would prompt an active reading.