USPS automatically creates a tracking number for an order once the shipping label has been printed which is why it looks like the order is not progressing but we assure you that it is being processed as quickly as we can. Until the order is given to USPS it's status appears as "Pre-shipment." Until the order is 21 business days (two weeks) past the last release date on the order (listed at the end of the product title for most items, dates are subject to change by publisher), it is not considered late.
We print orders in bulk based on the most recent release date for that order. It is then given to one of our staff to pull the books for said order. Once the order has been pulled it is given to another employee to quality control and ensure that the order is correct. It is then packed and given to USPS to deliver. Some orders can take longer than others to fill if there are a lot of books or if the books are old because they are located in our warehouse and have to be retrieved before the order can be packed.