It works as sabotage on Amazon listings because Amazon uses reviews with certain keywords as lead indicators for product contamination or other issues. So if you want to sabotage a competitor's vitamin pill the day before Prime Day, you have an entire building full of people leave variations of "taking this made me feel nauseous" or "this gave me a headache" and "weird chemical odor" after purchasing the product. Either the automated systems will flag it or complaints will flag it for review.

Software can't actually poison people in a physical sense, so generally the software marketplaces care less about signals from reviews like those.