I'd say 25 minutes of commercials and previews is unusual, but it is the summer, and they are trying to rope rabid SF fans like you into their other movie offerings, figuring you for a "niche market" and figuring you for a sucker in the bargain. Hollywood is not pretty these days, their marketing of the movies is very formulaic, but sometimes a great director and a great movie can survive their own hype.
"Suggested by" Isaac Asimov? That reminds me how in Canada we have President's Choice (brand) sauces, usually named in the form of "Memories of [place name] sauce". So a fiery jerk chicken sauce might be called "Memories of Kingston [Jamaica]" sauce but a milder variety would be called "Vague Memories of Kingston" sauce.
BLADE RUNNER is my all-time fave movie. The androids are vicious yet you have to empathize with their plight. Overall I like "cyberpunk" SF: near-future, high-tech, low morals. Other great SF movies I can recommend are THE FIFTH ELEMENT (most expensive movie made under the banner of France), UNTIL THE END OF THE WORLD (a gentle France/Germany/Australia production that's a light-hearted romp around the near-future world), JOHNNY MNEMONIC (Keanu Reeves plays, what else, a cyberhacker as well as a special courier smuggling data in his brain), MINORITY REPORT, and FREEJACK.
Also, RUN don't walk and get the DVD set of the one and only season of FIREFLY. This is a kind of 14-episode SF/western. An ex-war veteran on the losing side against an American-Chinese "Alliance" ekes out a living as a smuggler in a Firefly-class starship, accumulating an unlikely crew. Amazing ensemble acting and intimate shipboard sets. The DVD format is so compact that many video stores will rent out this set for week-long periods. The FOX network messed up the character development by showing episodes out of order, but its video/DVD release was impressive enough to encourage a movie, SERENITY, coming out next year.