Avoid promoting products that mostly create one-time customers.
Each product you promote has the potential to create multiple orders per customer. Some products are weak and don't lead to many repeat orders, while other products get customers hooked.
Avoid promoting these dead-end products in important places (e.g. homepage, email, ad campaigns). Save them for upsells, cross-sells, or as filler.
Otherwise your wasting much of your acquisition budget on one-off customers.
Eric Davis
Analyze your customer's behaviors before they defect
Your customers aren't yours forever. Some might have defected today, never to be seen again.
You need to analyze your customer behavior so you can reach them before they defect.