Are you launching a new collection on your store? If so, you could create a private link that doesn’t appear in your navigation a few days before making it public for everyone else.
You can mention that the link is exclusive to your VIP customers and that no one else can see it.
This type of customer service gives your best customers first access to new products that they can rave about online. As your following grows in popularity, your customers will create a viral effect for these secret collections.
You can also hide your secret collections on 404 pages or in a hidden part of your website ultimately surprising customers who stumble upon it by accident.