There are four parts to getting better margins in your e-commerce business:
Reduce customer acquisition costs - you could increase your margins through the optimization of your advertising spend and your creatives. You can do this by fine-tuning your targeting - by reaching the right audience with the right message, you increase your chances of converting them to paying customers, giving you more bang for your marketing buck.
Focus on customer retargeting and retention - research shows that it costs 7x less to retain an existing customer than to acquire a new one.
Optimize your landing pages and checkout funnel - by maximizing each customer’s cart order value and minimizing cart abandonment, you’re essentially optimizing your profitability. You can increase your customers' order value by cross-selling, upselling and bundle selling. You can minimize cart abandonment with an effective retargeting email campaign.
Lower operational costs - look to decrease your fixed costs by negotiating your storage and shipping costs, improving your operational efficiency, and also try to negotiate better terms with suppliers, switch suppliers or order a greater volume of product to improve economies of scale.