Oh, it was definitely paid! As another mentioned, a year later they spent $16 million on an ad campaign for Mission: Impossible, a movie they got the PowerBook to too late and that didn’t have any of the Mac UI in the film.
But the best part was that Gil Amelio, the CEO at the time (and the third in like 36 months or something) ignored all of his lieutenants and shipped that PowerBook, even tho it had massive problems (and later, I think exploding batteries) but it shipped late so they couldn’t get it out on shelves to take advantage of the commercials and product placement.
But Amelio did get one to Whoopi Goldberg, who called about one for her nephew or something. Almost all of them were recalled, however. Amelio shared this story in his book as if he should be proud he got Whoopi Goldberg a broken computer.
Apple still does product placement in certain films and TV shows (not just Apple TV stuff) but tried to keep it on the downlow.