Both FedEx and UPS send notification emails as soon as we generate your shipping label. The initial notice states something like "billing information received" or "pickup information received". It's deceptive if you're not familiar with their system in that it quotes a delivery date and leaves the impression the package itself has been picked up.
We generate a shipping label as soon as we receive payment. That triggers the email with the tracking number. But a guitar still has to be pulled from inventory, go through a final inspection and be packed for courier pickup. FedEx requires one day notice for ground shipments so the normal time from payment to shipping is one, or occasionally, two business day(s). Meanwhile you're chomping at the bit for your new guitar and getting upset every time a delivery truck passes your driveway.
Being able to advise a customer of the location of their guitar by email is a great tool. You get a notice at every stage of the delivery cycle. But we wish the courier companies would re-word that initial e-mail to make it a whole lot clearer!