While not specifically about ecommerce, r/smallbusiness is a great place to ask questions and learn from others who are starting, owning and growing a small business.
Learn more about FB Ad Buying and connect with other FB Ad Buyers. Compare different advertising tools, tips, tricks, and learn from industry-leading veterans. A group with 100,000+ members.
EcomHunt is a curation of the best new products, every day. Discuss winning products to sell via your online store.
VerumEcom focuses on providing high-quality training and resources for people looking to either start their first e-commerce business or take their existing business to the next level.
Join the r/Dropship subreddit community to discuss the business of dropshipping, from the entrepreneur side of the table. It's a great place to share resources, solve problems and have serious discussions on issues that other entrepreneurs face.
If you're new to the ecommerce game and just about to make the plunge, Shopify Newbies is a strong group with close to 100,000 members that can help you get started on your Shopify ecommerce business journey.