Import pdf files to google play book application I want to import my own PDF files to google play book reader and read them using this application. But without any hacking I cannot read not purchased PDFs in google playbook.

I'm not looking for an alternative because they are not good enough (such as ezPDF or Moon+ and ...)
I'm afraid this is impossible. It's the number one most requested feature but, as far as I can tell, there are no plans to implement it. I suspect this is because Google is under quite a lot of fire for enabling piracy. Allowing people to load their own books into the books app would intensify that.