Opt-in and opt-out numbers relate to user consent or subscription behavior—how many people choose to engage or disengage with a service, newsletter, or marketing offer. While these metrics can reflect the effectiveness of marketing campaigns, they do not directly measure SEO performance. SEO success is better evaluated through organic traffic, search rankings, and engagement metrics rather than opt-in or opt-out figures. It involves factors such as keyword usage, backlink quality, site structure, content relevance, and user experience.