Loyalty glossary · 8. Technology and architecture (25)
Sso
SSO is single sign-on, an authentication pattern that lets a loyalty member log in once and then move across the programme's own site, partner sites, and linked tools without repeating credentials.
Friction kills accrual. A loyalty programme that forces members to sign in separately on every partner site is telling them not to bother. SSO removes that repeated login, and the effect shows up in active member rate, because a member who can move from the programme's own site to a partner without a new password is more likely to complete an activity that counts for accrual.
The danger is not SSO itself, it is what a badly implemented SSO hides. When one identity token replaces separate partner logins, the programme can lose the signal of which partner delivered which action. That matters for activity-based qualification, where a tier is earned by specific behaviours, not by simply being present.
Take a worked example, because the argument only lands with numbers. A programme with 10 partners expects a member to complete 2 stays per year without SSO. With SSO, the same member completes 3 stays per year. That is 1 stay more. If each stay earns 500 points, the member accrues 500 points. Scale that across 10 partners and the programme moves from 2 stays to 3 stays per member, a 50 percent lift in activity-based qualification.
The only acceptable SSO design is one that preserves attribution. SSO should not merge the member's identity into a single blob that hides which partner delivered the stay, the point, or the tier progress. It should pass a stable identifier to each partner so that accrual, active member rate, and activity-based qualification are computed on the same event data as before.
Most SSO implementations fail because they optimise for convenience and not for data. A member who authenticates once and then browses a partner catalogue without any partner-specific tracking leaves no trace for activity-based qualification. The programme then cannot distinguish a member who completed three stays at partner A from one who merely logged in and looked. That is not a loss of convenience, it is a loss of the programme's ability to award the right tier.