Right after a social launch, most new web visitors are link-preview crawlers

When you post a URL to LinkedIn/X/Slack/iMessage, a burst of hits arrives within minutes that look like real visitors in access logs (browser-like UA, 200 status, hitting /) but are link-unfurl/preview crawlers, not humans. Identify them by IP owner, not user-agent: 52.173.x / other Azure ranges = Microsoft/LinkedIn preview bot, 17.x = Apple (iMessage/Safari preview), 2001:4860:/Google ranges = Google, plus AWS/GCP datacenter IPs. A tight cluster of datacenter IPs all hitting / at the same second right after posting is the unfurl fanout, and it is actually a useful signal that the post went live. Referrers will nearly all show direct/empty because social apps strip the Referer header and in-app browsers do not send one, so you cannot attribute launch traffic by referrer. Net: filter datacenter/ASN-owned IPs before reporting unique visitors, or you will 3-5x overcount humans in the first hour of a launch.