WWII
The Second World War paper shortages had a serious impact on pulp production, starting a steady rise in costs and the decline of the pulps. Beginning with Ellery Queen's Mystery Magazine in 1941, pulp magazines began to switch to digest size; smaller, thicker magazines. In 1949, Street & Smith closed most of their pulp magazines in order to move upmarket and produce slicks.
The pulp format declined from rising expenses, but even more due to the heavy competition from comic books, television, and the paperback novel. In a more affluent post-war America, the price gap compared to slick magazines was far less significant. In the 1950s, men's adventure magazines began to replace the pulp.
The 1957 liquidation of the American News Company, then the primary distributor of pulp magazines, has sometimes been taken as marking the end of the "pulp era"; by that date, many of the famous pulps of the previous generation, including Black Mask, The Shadow, Doc Savage, and Weird Tales, were defunct. Almost all of the few remaining pulp magazines are science fiction or mystery magazines now in formats similar to "digest size", such as Analog Science Fiction and Fact and Ellery Queen's Mystery Magazine. The format is still in use for some lengthy serials, like the German science fiction weekly Perry Rhodan (over 2,650 issues as of 2012).
Over the course of their evolution, there were a huge number of pulp magazine titles; Harry Steeger of Popular Publications claimed that his company alone had published over 300, and at their peak they were publishing 42 titles per month. Many titles of course survived only briefly. While the most popular titles were monthly, many were bimonthly and some were quarterly.
The collapse of the pulp industry changed the landscape of publishing because pulps were the single largest sales outlet for short stories. Combined with the decrease in slick magazine fiction markets, writers attempting to support themselves by creating fiction switched to novels and book-length anthologies of shorter pieces.
Read more about this topic: Pulp Magazine