Behavior-wise, it's best for a customer to purchase again for their own purpose. But not all merchandise can sell that way, especially with big-ticket items like dining tables, computers, or blenders. Sometimes you'll get repeat purchases for them but it'll be rare.
Selling gift cards might be an option. If your customers love your products but don't need to buy frequently, you can offer gift cards they buy for loved ones. This acts like a stronger form of word-of-mouth advertising.
Shopify includes support for gift cards, including some advanced features (e.g. free cards as incentives, gift card discounts) though not all themes support everything yet.
Taking the time to get them setup or updating your theme to support them is a great use of time before the winter holiday season.
Eric Davis
Optimize your promotion timing to save money and attention
Repeat Customer Insights will analyze a ton of customer behavior data for you, including their buying cycles.
If you knew exactly when the majority of your customers were ready to buy again, you can increase your orders and profit just by tweaking your message timing.