Sometimes it's the small details. Remember all the microtransactions in Ubik? "insert coin to open this door" (to his own apartment!) etc.
I suspect the microtransaction idea was in the air in the 1960s. Nikolai Nosov's "Dunno on the Moon" (https://en.wikipedia.org/wiki/Dunno_on_the_Moon) which is a Soviet satire of American capitalism describes exactly the same idea implemented at the "Economy Hotel" That's 4 years before Ubik.