distributing comics not on a sale-or-return basis, but in limited runs according to sales predictions from the retailers themselves, over-printing and overhead costs could be drastically reduced. From the 1970s to the present day, comics publishers have been targeting more and more of their titles to collector audiences with features such as limited editions, the use of high quality paper, or the inclusion of novelty items. The speculator boom From roughly 1985 through 1993, comic book speculation reached its highest peaks. This boom period began with the publication of titles like Batman: The Dark Knight Returns and Watchmen and "summer crossover epics" like Crisis on Infinite Earths and Secret Wars. After Watchmen and Dark Knight Returns made their mark, mainstream attention returned to the comic book industry in 1989 with the success of the movie Batman and again in 1992 with "The Death of Superman" storyline. Once aware of this niche market, the mainstream press focused on its potential for making money. Features appeared in newspapers, magazines and television shows detailing how rare, high-demand comics such as Action Comics #1 and Incredible Hulk #181 (the first appearances of Superman and Wolverine, respectively) had sold for thousands of dollars, with Action #1 breaking the $1 million mark. During this time, mainstream comic book publishers began to pander specifically to the collectors' market. Techniques used included variant covers, polybags, and gimmick covers. When a comic was polybagged, the collector had to choose between either reading the comic book or keeping it in pristine condition for potential financial gain, or buying two or more copies to do both. Gimmicks included glow-in-the-dark, hologram-enhanced, die-cut, embossing, foil stamped or foil-embossed covers. Gimmicks were almost entirely cosmetic in nature, and almost never extended to improved content of the comics. However, many speculators would buy multiple copies of these issues, anticipating that demand would allow them to sell them for a substantial profit in the future. Low-budget independent publishers also proliferated during this period. The low price of producing comics, and the ease and efficiency of the direct market enabled fly-by-night publishers to flood the market with product, much of it of low quality. A number of these publishers attempted to cash in on current trends — for every Teenage Mutant Ninja Turtles (itself a nod to the popularity of the Uncanny X-Men), there were multitudes of blatant rip-offs like Adolescent Radioactive Black Belt Hamsters, Geriatric Gangrene