There has been an increasing trend of soliciting donations for a store's charity partner by cashiers at grocery checkouts. A number of such charity appeals use the philosophical concept of Karma, which suggests equivalent outcomes to an individual's actions. Even though this concept is inherently neutral in stating the corresponding outcomes to both types of actions (i.e., good or bad), a majority of donation appeals use Karma's negative tenant alone (e.g., “when you don't donate, someone in your neighborhood goes without food”). Where previous message‐framing research has mainly focused on donation outcomes (e.g., pledged‐dollars), this research is a first of its kind to not only investigate the impact of using Karma's negative (vs. positive) tenants in prosocial messaging separately, but to also assess its effects on the largely‐ignored but critical store outcomes of purchase satisfaction and revisit intentions. Results from four scenario‐based experiments demonstrate that using a negative (vs. positive) Karma connotation in donation appeals at grocery checkouts significantly lowers consumers' purchase satisfaction at the store as well as their intentions to revisit the store in the future (with no major impact on the donation outcomes). Following established research on negativity bias, affect and moral consciousness, this research also shows that instead of emotions, lowered consumer mood mediates these effects. Furthermore, it evidences that the negative effect of using Karma's negative (vs. positive) connotation in checkout donation solicitations on the store outcomes attenuates when consumers' grocery basket consists of more hedonic (vs. utilitarian) products based on the former's mood‐uplifting properties.