One way to acquire new customers and build loyalty is to have try before you buy products.
You could some something complex like sending orders and delaying the charge for 30 days but you'd be open to a lot of fraud.
Instead I'm talking about creating sample-sized products and letting customers buy them for just shipping/handling. Basically free samples.
With strong, high-quality products, these free samples can remove most of the buying risk for your customers. Customers will try the sample, benefit, and want to order the full-sized version.
That'll help customer acquisition.
By making the samples free and promoting them to your existing customers, you can also convince some customers to branch out and try new products (or variants). They are likely to also order some additional products because they are paying for shipping already.
This will help build customer loyalty.
Once you have your initial samples, you can adapt and optimize them. 1 sample or 10 samples or monthly rotating sample? How much does the sample include? Include a coupon incentive or not? Etc, etc
Refine your automated marketing campaigns with better timing
When building any automated marketing campaign that sends messages over time, you need to know how long the campaign should be and how long to delay the messages. The Customer Purchase Latency metrics calculated by Repeat Customer Insights can help you figure out that timing.