Actually, I noticed on some packages I mailed in the last few days that they appear to be tracking everything. I had some small things that would have fit into the $6 Flat Rate boxes (with tracking and insurance). But with careful packing in some padded envelopes, I was able to mail them 'First Class Parcel' (or something like that - under 13 ounces) for $3 - $4 each and save a few bucks.
They placed a large label on each package with bar codes and a tracking number, which was printed on my receipt, so I asked about it. They said that it was for their tracking purposes - not something I could look up on line. So it was not of special value to me, but suggested that they may be trying to improve their overall tracking of parcels.
Philbert