What Makes A Discontinued Post Office Cancellation (Dpo) Rare

Hello

I was just doing some digging through a bunch of old 1900-1920 postcards which were purchased many years ago at an estate sale. I observed that several of my cards appear to have been cancelled by DPO's. I know that there are many DPO's around the country, however, I'm not aware of what makes one DPO more rare than another. For example, two of my cards are from WV which were cancelled in Deep Valley and Central Station. Thanks for the help!

Several different circumstances make a cancel scarce. Main one is the length the cancel was used or how long the post office was open.


Peter

I agree with Peter, there are many factors in the rarity/value of a DPO. Evaluating postal history is an art and many factors have to be taken into account. A DPO is one factor.

Consider a crude quantification: Supply = (length of cancel use)x(population served) = total mail volume. Less a survival factor. But enough math.

That said, and to go onto a tangent ... not all DPOs are created equal. Many are truly scarce, yet many are very common. Mentally, I draw a distinction among DPOs, specifically ...

1. A DPO that withered away and was closed, or closed due to construction of a dam, etc. - a true DPO in my opinion.

And lesser degrees of DPO-ism:

2. A DPO due to being made an RFD route of the nearby town, which happened to 1/4 to 1/2 of the towns in many rural counties in the 1900-1915 era.
3. A DPO due to being made into a station or branch of a nearby town. An example being Indianapolis which adopted a county-wide "Unigov" system and many of the independent towns in the county became stations or branches of Indianapolis. Are they DPOs?
4. A DPO due to a name change which happened a lot in the 1891-94 era with Postmaster General John Wanamaker's name standardization program to make two words into one, to make -burgh into -burg, -borough into -boro, centre into center, etc. These name changes for purposes of standardization are NOT real DPOs in my opinion, but others will disagree.

In the case of the OP's two cards, Deepvalley became a rural route out of Central Station, WV, in 1918, and
Central Station was discontinued in 1984 with mail being handled through West Union.
Both are DPOs, yet is the rarity the same? Is the value the same? Complex isn't it?

Very interesting comments and thank you for all the input. I would imagine the Deep Valley, WV cancel is probably the rarest. Looks like the population in that area of WV at that time was very sparse and probably is the same today.

I would guess that only a low number of those cancels exist today. Thanks for the help!

On the flip side, there are rare/valuable cancels from large POs which are open. For example there are trial machine cancels from Chicago c1900 for which there are less than a dozen known copies and which sell for several hundred dollars when they come to market.