BIIThis story was delivered to BI Intelligence "E-Commerce Briefing" subscribers. To learn more and subscribe, please click here. Online grocery services are growing quickly in the US as shoppers become more comfortable with buying grocery products online. But the market is filled with competition and as these companies try to gain market share, they're having to adjust their business models to maintain an edge. Here's what a few services are doing now: Instacart announced it's cutting back hours for its in-store cashiers in New York City, reports Quartz.