The milestone issue had over 380,000 sales.
Source: Comics Beat
Image announced that The Walking Dead #100 was the bestselling comic of the century, having sold over 380,000 copies last week. While the phrasing was technically correct, more accurately the comic was the bestselling comic of the last fifteen years, since December 1997, when Image released Darkness #11. That issue also had multiple covers and beat out heavy hitters such as Avengers and Iron Man, both of which had begun new series with shiny new #1 issues. For comparison purposes, the last issue of The Walking Dead #99 sold approximately 56,000 copies.
While it's doubtful that The Walking Dead can maintain such inflated sales figures, it should be interesting to see whether there's any noticable boost in sales. The series is one of only a few titles in the industry which actually gains sales as time goes on. Most series battle attrition throughout their runs, forcing companies to rely on marketing gimmicks or creative shake ups to boost sales. While there's no doubt that this was a classic gimmick, the fact remains that the series has proven it can gain readers every single issue.
Written or Contributed by: ThanosCopter