Measuring the Citation Gap

428 small and mid-sized business websites across four countries, measured as a retrieval client sees them — not as a browser renders them. Of 349 access-eligible sites, 187 (53.6%) satisfy the access preconditions but fall below the protocol's extraction-readiness threshold. The gap is shallow: 114 of the 187 fail exactly one precondition, most often a top-level heading, structured data, or a meta description. llms.txt adoption is 20% and concentrates among sites already outside the gap.