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.
Doom WAD
"Doom" WAD is the default format of package files for the video game "Doom" and its sequel "Doom II: Hell on Earth", that contain sprites, levels, and game data. WAD stands for "Where's All the Data?". Immediately after its release in 1993, "Doom" attracted a sizeable following of players who created their own mods for WAD files—packages containing levels, graphics, and other game data—and played a vital part in spawning the mod-making culture which is now commonplace for first-person shooter games. Thousands of WADs have been created for "Doom", ranging from single custom levels to full original games; most of these can be freely downloaded over the Internet. Several WADs have also been released commercially, and for some people the WAD-making hobby became a gateway to a professional career as a level designer.