DC Comics, much like their rival Marvel, has come to increasingly use and rely on comic book events to spur sales and boost interest in their many titles. These expansive, epic sagas have led to some of the company's best stories, but they've also led to some of the most controversial moves at DC. One of the ways an event can annoy readers is the over-saturation of needless tie-ins, which often outpace the core story.
Source：https://www.cbr.com/best-dc-events-too-many-tie-in-comics/
