Google, Twitter, Fb Are Not Accepting My Squeeze Page

Hello,

I have a pretty simple squeeze page, giving away a PDF in exchange for an email.

For some reason neither fb, twitter or google ads accept it, while at the same time I see many sponsored ads asking for emails.

Can anyone shed light on this matter?

Is it harder to get an ad accepted in exchange for email leads nowadays?
Do I have to give it a price?

Thank you