I will do a PDF submission to 15 document sharing sites

Sharing your content online like pdf has a positive impact on google ranking and how they perceived a content with a link . This can boost your popularity online, when a user found your pdf doc there's a chance they will likely download it and  share your doc to other users or into their social networks.

Your pdf file that you will  send to us must have an anchor text/links for visitors to visit your website. Actually search engine  can actually read and index a pdf file.