Yes, it is best to auto-enroll members into the loyalty program, as soon as they log in or create an account on your site.
Your goal should be to get as many members enrolled in the loyalty program as possible. Auto-enrollment minimizes friction for program signup.
Loyalty programs like Zinrelo are priced on a per-member basis, therefore, some businesses are hesitant to add members to the program thinking that their costs will go up. However, that approach is counter-productive. The fundamental purpose of a loyalty program is to maximize user engagement leading to higher repeat sales and more per-customer revenues. A loyalty program usually charges a few cents per member per month. Even if 1% of your entire user base gets engaged each month and makes a purchase, the program will generate positive ROI. Usually, 3-5% of your user base will get engaged, leading to higher repeat sales. Therefore, a business should get as many users enrolled in the loyalty program as possible. The best way is to auto-enroll members and offer an opt-out option.
A welcome email should be sent to auto-enrolled members. Make sure that you emphasize in your welcome email that they are signed up for free. Highlight the benefits of the loyalty program. Welcome email should also clearly tell members how they can opt out of the program if they wish.
Members can opt out of the loyalty program at any time by visiting the Profile section. Members who opt out are not counted in the loyalty member count.