Doom (1993 video game)
Because id planned to self-publish the game, as the game neared completion they had to set up the systems to sell the game. Jay Wilbur, who had been brought on as CEO and sole member of the business team, planned the marketing and distribution of "Doom". He felt that the mainstream press was uninterested in the game, and as id would make the most money off of copies they sold directly to customers—up to 85 percent of the planned US$40 price—he decided to leverage the shareware market as much as possible, buying only a single ad in any gaming magazine. Instead, he reached out directly to software retailers, offering them copies of the first "Doom" episode for free, allowing them to charge any price for it, in order to spur customer interest in buying the full game directly from id.
Development of Doom
Over spring and summer of 1993, Carmack worked on improving the graphics engine of the game. After Romero's level designs started to cause problems with the engine, he researched and began to use binary space partitioning to quickly select the portion of a level that the player could see at any given time. Additionally, in March 1993, the company had to stop work on the game while the team spent three weeks building a Super Nintendo Entertainment System port of "Wolfenstein 3D", after the contractor who had agreed to do the port proved to have made no progress. Taylor, along with programming other features into the game, added cheat codes; some, such as 'idspispopd', were based on ideas their fans had come up with while eagerly awaiting the game. By fall, the game was nearing completion, with players eager to see it, spurred on by a leaked press demo. John Carmack began to work on the multiplayer component of the game; within two weeks he had two computers playing the same game over the internal office network. Soon, the office was playing four-player Deathmatch games.