Private seller. Really, it's partially my fault for not inquiring about the method of shipping first. I just kind of figured that most people use Fedex Ground or UPS. I would even have been okay with it taking awhile to get here if I only knew where it was along the way. USPS calls is "tracking", which isn't exactly true, at least in the way Fedex or UPS does it. It basically goes into the black hole of the USPS system and they will send you an update (presumably) when it turns up at the local post office.
Lessons learned: always, always, always confirm the shipping method before buying or trading. And make sure that it's a real tracking number that a call to the service desk can more/less pinpoint where the package is en route. this will save a lot of angst.