Amazon's Prime Day is a good example of rewarding your best customers.
Even though you have to pay to becoming a Prime member, Amazon has repeatedly said how those customers spend more than other segments. It acts as an interesting way to let your customers self-segment.
Whether you love or hate Amazon, you can still learn from them.
Creating a special deal day or two for your VIPs or loyal customers isn't anything new. But instead of hiding it, marketing only to your VIPs, or putting the deals in a protected collection, you'd shift the marketing and promotion to the forefront.
Banners, packaging, ads, and even concerts have been used by Amazon to promote Prime Day.
You could even let regular customers get in on the deals too. Either sell them a membership like Amazon does, let them buy a "day pass" for a token amount, or not even check for membership during checkout.
The big point of Prime Day is the marketing push.
If you don't yet have a segment for VIP customers, the Customer Grids in Repeat Customer Insights can make that easy. There are 30+ segments created automatically in there so you'd just need to pick a few of them to use and you'd be all set.
Customer behavior analysis for better Shopify store performance
The Shopify App that increases repeat customer purchases through customer behavior analysis.