If someone sends a book..buys pbs postage..the book can be "seen" with tracking. (Waiting pickup..label created) and that's the only scan, if it goes lost does the requestor get their credit back?

Yes

Michele - if a book is sent using PBS Postage the sender does not receive a credit until the sender has marked the book as "Sent". 

If the book is never scanned by the PO (it happens) and times out (about 30 days)  it will be marked as "Lost In The Mail" - the person who ordered the book will get their credit back, The sender may or may not have the credit given to them taken back - the sender should check their credit Registry to ensure a credit has not been removed from their account - if a credit has been removed (it happens) then the sender will need to contact the PBS Team and ask for its return. 

Jist because it was marked as 'Mailed' by the sender does not mean it was actually mailed, and just because it was never 'scanned' by the PO does not mean it was never processed by the PO. 

The policies of scanning are local, often based on staffing and equipment. Some post offices scan everything if their location is in question of closing. Some seen to never scan media mail. 

Items are more likely to be scanned at the sorting hub. 

With PBS postage both parties should receive their credit back when a book goes lost.

Too many lost books will cause PBS to contact you. Once you reach the statistical point that the computer system has flagged you for human contact. 

Thanks everyone!

If the book goes lost in the mail, the requestor gets their credit back ALWAYS, regardless of how postage was purchased.

If the sender purchased postage from PBS, they get the credit when the book is mailed, which they keep regardless if the book is ever marked received or not.

That's what the extra money you are paying to PBS for postage is for ... "Credit Assurance".

When a book is marked received, the sender's credit comes from the requestor. When a book is never marked received, if the sender purchased postage thru PBS, the extra credit that the sender keeps comes out of PBS's pocket if the book is never marked received.