A question that recently came up was this:
If an incoming link to a site is listed in the footer of an ebook and is in a PDF doc, is that link read as an incoming link with Google?
Yes. Google does count links in PDF files as incoming links.
See the following Google search example:
This search combines 2 operaters;
the link: operator and filetype: operator.
Searching for links to www.adobe.com that are only in PDF documents.
The results of the search prove beyond any doubt the answer provided is correct.
“Google does count links in PDF files as incoming links.”