{
 "title": "Probegrade vs. directories that sell placement",
 "compared": [
  "Probegrade",
  "Directories that sell placement"
 ],
 "rows": [
  {
   "dimension": "How sources are ranked",
   "probegrade": "Automated probe measurements",
   "them": "Often by payment, popularity or editorial picks"
  },
  {
   "dimension": "Effect of paying",
   "probegrade": "None on scores; sponsored slots are labeled and separate",
   "them": "Paid listings can appear above unpaid ones"
  },
  {
   "dimension": "What's measured",
   "probegrade": "Uptime, latency, schema validity, freshness, price",
   "them": "Usually nothing measured continuously"
  },
  {
   "dimension": "Audit trail",
   "probegrade": "Hash-chained probe archive per edition",
   "them": "Rarely published"
  },
  {
   "dimension": "Payments for agents",
   "probegrade": "x402 gateway, billed per call",
   "them": "Typically not offered"
  }
 ],
 "note": "Category comparison. It describes common patterns, not any specific company.",
 "updated": "2026-10-17",
 "url": "https://probegrade.com/compare/pay-to-list-directories/"
}