If you are a frequent Instagram user, chances are you may have noticed some posts in your feed with a small shopping bag icon, tucked in the lower left-hand corner.  This is Instagram’s Shop feature, which includes products offered by hundreds of brands and retailers across the world — and it’s a wise investment from the social media platform.   Analysts told Business Insider that Instagram’s move to shopping will be so successful that it will generate $10 billion in revenue by 2021. Using the Shop feature is easy, too. Any post with a shopping bag icon has a product or products linked to it — just tap on the product name, and you’re taken to the description page where you can save it for later, or buy it now.  Some products are available to purchase without even leaving the app, while others take you to the retailer’s website to finalize the transaction.  Some retailers partner with Instagram to provide a check-out process within the app. Most of those retailers are featured on Instagram’s @shop account.  Instagram’s @shop account features many retailers that have items available for purchase on the app. Meira Gebel/Business Insider 2. ...