Alquien.
U.
If your talking about mobile app downloads, its fine to link to the app pages through adwords, but theyll still be reviewed.
For normal sites, you cant link to executable file download, no auto downloads (like timeouts), etc. If your walking the gray line, your most likely not going to be approved on googles end.
I was talking about having a PDF download with related content just for content/QS. Does goog/bing review/grade the content of the PDF like they do with onsite content?