The consensus here seems to be that it's an effort to promote Scribd, but I had always assumed that it was an attempt at trying to be helpful to those who prefe

The consensus here seems to be that it's an effort to promote Scribd, but I had always assumed that it was an attempt at trying to be helpful to those who prefer to remain within a browser, and to those who hate opening PDFs. At least, it serves that use case to me.