What's the best linkbuilding strategy regarding Document Sharing?

Hi to everyone,
As I mentioned in the post title, I want to know what actually is the best strategy for linkbuilding regarding the Document Sharing (PDFs).
I'm actually willing to upload PDFs on document sharing sites.

What's the best (safest) way to upload document on those website? Can I simply use printfriendly.com to transform my website articles into PDFs or have I to use some PLR articles or unique content written by me with backlinks to my website?

Last question: can I upload the same PDF onto several websites or it's better to upload different PDFs for each website (for example, I upload on Scribd the PDF "x", can I upload it again on 4shared or have I to upload the PDF "y")?

Thanks to all

I don't know about best, I'm using GSA Ser Document sharing option

A viral PDF is the best and safest way to do it. If your content isn't really easy to viralize, then blast using a bought service or a tool like GSA.

What's the difference (in terms of quality) between GSA Ser Document sharing option and a manual submission (printing as PDF my websites pages)?

Does GSA Ser generate automatically PDF giving him some sort of spinned text?

bartosimpsonio said:

A viral PDF is the best and safest way to do it. If your content isn't really easy to viralize, then blast using a bought service or a tool like GSA.

Click to expand...

viral pdf? you mean using the same pdf article on multiple document sharing sites and show that it is going viral?!

would appreciate some insight on using the same pdf on different article sharing site vs. unique pdf for each site. thanks