The Douglas Adams comparison isn't half wrong, though I like to think of Ubik (as with several of PKD's other novels) as being spiritually closer to Kurt Vonnegut Jr. Like Vonnegut, PKD's stories are often an incongruous combination of tragedy and deadpan comedy, though his style is of course quite different.

Ubik is meant to be a colourful and out there. Take the descriptions of characters' outfits, for example. One is wearing "a cowboy hat, black lace mantilla and Bermuda shorts", and that's a female character. Ubik was beloved by French critics who compared him to Alfred Jarry, the surrealist. The argument with the door is meant to be ridiculous, but also predicts hostile technology. Today, I just had to argue with a chat bot in order to cancel my NY Times subscription (they also allow you to do it over the phone; but you can't just cancel), which is the kind of "banal dystopia" that PKD loved to conjure up.

Adams was also influenced by Vonnegut. In The Sirens of Titan, the entire plot — involving time travel and an attack on Earth by Mars — is orchestrated by an extraterrestial being simply because he needs a spare part for his spaceship. You find that kind of cosmic irony in Adams a lot.