Scribd is a nightmare to use on a mobile device as well. I can't count the times I've open an article on my phone and wanted to view the linked PDF, only to get a brand new web page whose text is too small to read, can't be resized, and zoom buttons are unclickable because they overlap. Oftentimes there's a tiny "download PDF" link located in a the upper right corner which is incredibly difficult to press; after repeatedly attempting to press it for an inordinate amount of time, I can usually finally load it into a native PDF viewer.

In short, just supply a PDF link.