“GPP feature?” said Arthur. “What's that?”

“Oh, it says Genuine People Personalities.”

“Oh,” said Arthur, “sounds ghastly.”

A voice behind them said, “It is.” The voice was low and hopeless and accompanied by a slight clanking sound. They span round and saw an abject steel man standing hunched in the doorway...

“Ghastly,” continued Marvin, “it all is. Absolutely ghastly. Just don't even talk about it. Look at this door,” he said, stepping through it. The irony circuits cut into his voice modulator as he mimicked the style of the sales brochure. “All the doors in this spaceship have a cheerful and sunny disposition. It is their pleasure to open for you, and their satisfaction to close again with the knowledge of a job well done.”

As the door closed behind them it became apparent that it did indeed have a satisfied sigh-like quality to it. “Hummmmmmmyummmmmmm ah!” it said...

"Thank you the marketing division of the Sirius Cybernetics Corporation," said Marvin, and trudged desolately up the gleaming curved corridor that stretched out before them. "Let's build robots with Genuine People Personalities," they said. So they tried it out with me. I'm a personality prototype. You can tell, can't you?"