As well as sharing your Loyalty Card URL in store and online, you can produce a video.
As well as showing off your business, best practice videos show customers signing up, the experience (like location messages and push messages) as well as the rewards they will enjoy when they sign up.
And don't forget to add a link to your loyalty program at the end of your video.
Here's a fantastic example of a promotional video, from a restaurant chain using Loopy Loyalty.