Google should launch a contextual advertising product for PDF files

I've wondered for years why we don't have an AdSense for PDF product from Google (or others). Why can't I embed code from this hypothetical AdSense for PDF product into a PDF ebook I've written, and distribute it for free on the Internet. This hypothetical PDF shall be secured in such a manner that it shall open only when there's a Web connection available, so that ads can be pulled from Google's servers in real-time.

I believe that an AdSense product for PDF files can bring a revolution in the commercial use of the PDF format. It shall allow both experts and semi-experts to publish individual articles as well as full-blown ebooks in the form of well-protected PDF documents laden with advertising code, without worrying about unauthorized copying of their work. In fact, under this model authors will encourage free-distribution of their PDFs to more and more people.

Such a product shall allow website owners to publish select documents in PDF rather than HTML. Use of PDF shall provide the following benefits to the publisher:

1. Setting permissions using industrial-strength features of PDF
2. Not losing out on the per-document ad revenue available in regular Web documents
3. Providing the usual benefits of PDF files - such as a consistent layout, paper-like readability, etc. - to the users

Because the PDF format is such a tightly-knit format, compared to the relatively loose HTML format, I have a high degree of confidence that a well-designed contextual advertising product for PDFs will usher a revolution in the way PDF files are used. However, I also have a strong belief that a prerequisite for such a product's success is that the use of PDF files be made as seamless as the use of HTML documents currently is. Google's integration of PDF support in Chrome is a good step in that direction.

For Google, such a product can mean a new source of cash - whilst making minimum investment - to feed its desire for continued growth.