They make you taste the product then slap you in the face one second after.  
Yes, putting a nag up over content (especially which you don&#x27;t own) while someone is looking at it is the mental equivalent to slapping that person on the face.<p>Only on the internet does this seem to be a best practice.<p>(Furthermore there&#x27;s nothing inherent to the experience&#x27;s design that prevents it from being delivered to non logged-in users, the block is artificial, not a design constraint)