What’s the cost of a single bad review on Instacart? The app’s shoppers say it can mean the difference between making rent and falling behind.

The difference between a four-star review and a five-star review may not seem like much for Instacart users. But for the app’s contract shoppers, a single less-than-perfect rating can mean the difference between earning $25 per hour and slipping below minimum wage. In a first-person essay for Vox, Instacart shopper Ehud Sopher explained that the app directs the best-paying jobs to the best-rated shoppers. That means even a tiny difference in overall ratings, like a 4.96 instead of a 5.0, can have a dramatic impact on a week’s wages. “Customers possess a near-godlike judgment over shoppers, who never fully know which customers rated them and why,” Sopher wrote. Instacart shoppers have complained about the impact of even-slightly negative reviews since 2017.