(CNN) -- Pure products of Hollywood, "The Hunger Games" and "John Carter" were conceived, designed, stretched and pre-tested with one purpose: to lighten billfolds while satisfying mass appetites. These two movies seemed especially intent on seizing the wavering attention spans of young people with premises deeply rooted in science-fiction -- or, as some genre lovers might prefer to call it, speculative phantasmagoria. Same goals, different results. Drastically. Different. Results. Hunger Games, in case you hadn't heard by now, has exceeded advance expectations by reaping $155 million in its first three days of nationwide release. That's the third-highest opening tally in box-office history, just beneath the $158.4 million drawn from 2008's Batman sequel, "The Dark Knight," and not too far removed from the $169.2 million made last summer by "Harry Potter and the Deathly Hallows, Part II."
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Gene Seymour: "Hunger Games," "John Carter" exist to make money, appeal to masses
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But "Hunger's" returns went through the roof, he writes, "Carter's" fell through the floor
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Wildly expensive "Carter" seems old, he says, while "Hunger Games" is of the moment
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Seymour hopes young audiences are aware of Hollywood's hype manipulation
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