"In her last years, ironically," THe New Yorker wrote, "she became more and more popular. Her books, even in hardcover, sold between forty and fifty thousand copies in their first few weeks of publication. She received the C.B.E. in 1971. The Nicaraguan government put Poirot’s face on a postage stamp."

From The Guardian:

Little grey cells are set to be exercised up and down the country after the Royal Mail announced it would be releasing a series of Agatha Christie stamps packed with “hidden secrets” to mark what would have been the queen of crime’s 126th birthday on Thursday (September 15).

The six stamps are devoted to classic Christie mysteries, including her debut The Mysterious Affair at Styles, which Christie began writing 100 years ago at the age of 26, and another Hercule Poirot mystery, Murder on the Orient Express – appropriately enough a first class stamp. Each design includes microtext, UV ink and thermochromic ink. These concealed clues can be revealed using either a magnifying glass, UV light or body heat and provide pointers to the mysteries’ solutions.