Translations:Extension:Popups/50/en

Defines the fraction of users that should be subject to an A/B test. When enabled half of users in this group will see page previews. The rest will be divided into one of two buckets where previews will not show and the control group size will match the enabled bucket. If undefined, or 0, no users will be subject to experimentation and previews will be enabled for everyone unless $1 is enabled.