How to let search engines index form-locked PDFs

Question

I'm using download manager, that locks the downloading of PDF until the user fills out a lead form. But the data in PDF is valuable and should be indexed by search engines. Any idea how can I achieve it?

Answer 1

One way this could be done is through PHP user agent:

if(strstr(strtolower($_SERVER['HTTP_USER_AGENT']), "googlebot"))
{
    // what to do
}

If the user is Googlebot, display/redirect to the PDF file. If the user isn't Googlebot, show them the submission form to receive the PDF file.

However, it's worth noting that Google wants to know what you are showing its users. If it thinks you're linking to a PDF file but you're really serving up a form first it might not like that.

But detecting the user agent to determine if you're going to show the PDF or the submission form is probably the only way to accomplish what you're trying to do.