The 2½ cent postcards with the stamp image of King Willem III, issued in July 1889 are recorded with advertisings from the well known Dutch stamp dealer G. Keiser. The question collectors of Netherlands and/or Suriname postal stationery will have is, why is there a advertising from a Dutch company on a postcard from Suriname?
In October 1906 the Government was clearing out remaining stocks of demonetised (31 January 1906) stamps and postal stationery. To gain some money from the stamps rather than spending money on destroying them, it was decided to auction them off via the Government Auctions.
A part of the postcards ended up after the Government Auction at the stamp dealer G. Keiser & Zoon. On auction were 50 packs of 40 cards x10 of the 2½ cent and the same amount for the 2½ cent with attached reply card. Due to this large stock of postcards being auctioned the reason for the many offers for unused versus used cards seems answered. Beside that the 2½ cent postcards were only mentioned to be used inside Suriname, since that was the domestic postcard rate and it was explicit forbidden to send them to foreign destinations as the French text on the cards was missing. However uprated postcards to foreign destinations can be found.
The question is what is a dealer going to do with so many unused postcards, while the market is satisfied with the demand.
The stamp dealer G. Keiser decided to use them as advertising cards for his business. The normal postcards and postcards with attached reply card, where separated and overprinted with the advertising of his business in black and blue. It is not known if he sold the advertising postcards or handed them out as some kind of business cards, but the latter seems more appropriate to assume.
Which combinations are recorded?
So far the normal 2½ cent postcard is only recorded with the advertising printed in black, see image above.
The 2½ cent postcard, outward card, is only recorded with the advertising printed in black, see image below.
The 2½ cent postcard, reply card, is only recorded with the advertising printed in blue, see image below.
No numbers of overprinted advertising postcards are known, but it can be assumed that quite a few have been made.
For collectors of Suriname postal stationery such cards are a curiosity to add to their collection, but nothing more.