Sometimes I like only those pages of novels and comics which seems the most nice for me. Sometimes I like all the pages of the novel or comics, for example, if I think that author don't get enough support, and want to help them go to the Trending or Popular or just cheer them up. But sometimes I just forget to like.
As well as others here, I've liked stuff less in general, when I was just a reader (not the creator of online content) and didn't think about the "like" as something valuable.