Referrer

The referrer is a small note a browser passes along when somebody follows a link: this visitor came from that page. It is unglamorous plumbing, and almost every claim any analytics tool makes about where your visitors come from rests on it.

AI assistants have made that note unreliable in several distinct ways at once. Many people never click at all, so nothing is sent. Assistants used inside a phone app frequently pass no referrer, and the visit is recorded as though the person arrived from nowhere — filed as direct, the same bucket as somebody typing your address from memory. Google's AI Mode strips the source information out of its links deliberately.

The word for what remains is guesswork. When a visit arrives with no referrer, no tool can recover where it came from, because the information was never sent. Estimates can be made from timing and patterns, and reputable dashboards do make them — but an estimate presented as a measurement is still an estimate.

It is worth knowing the mechanism, because it explains a specific experience a great many businesses are now having: direct traffic rising for no apparent reason. That is often AI at work. You improved something, people are finding you through answers, and the only visible trace is a category that means we do not know.

The human translation is a customer who says a friend recommended you but cannot remember which friend. The recommendation happened. It worked. You will simply never be able to thank anybody for it.