>And it provides counterfeiting and fraud resistance, along with the ability to add detailed tracking to letters very cheaply. Yes, this is what I was curious

>And it provides counterfeiting and fraud resistance, along with the ability to add detailed tracking to letters very cheaply. Yes, this is what I was curious about. (For non-Americans' benefit: All USPS shipping is tracked with barcodes, except for stamped mail. USPS offering this would benefit merchants who would be able to ship very small/thin items in envelopes with tracking, and people in general who want to be able to follow their stamped letters' progress.)