Potboiler is used negatively to suggest something lacks artistic merit and is purely for income. She didn't expect critical acclaim; the book was a potboiler, after all.
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Slightly Derogatory
'Potboiler' can imply a work is less respected or not taken seriously by critics. His latest movie is a mere potboiler compared to his former masterpieces.
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Cultural Usage
Although 'potboiler' relates to any creative work, it's often used in publishing and film industries. The studio wanted a potboiler that would rake in money from summer audiences.