Nielsen Norman Group put numbers on the first moments of a page visit back in 2011, using survival analysis on page dwell times. The shape of the curve is the finding. Pages do most of their dying in the first ten seconds.
Survive those and the odds improve. Visitors who stay past 30 seconds settle in, and many stay for minutes. Statisticians call the pattern negative aging. The page gets safer the longer someone stays, like a party that stops losing guests once the awkward first round of introductions is over.
- 10sthe window where most abandonment happens
- 30spast this point, visitors settle in and stays lengthen
- <60sthe average page visit, start to finish
Nielsen Norman Group, 'How Long Do Users Stay on Web Pages?', 2011.
Ten seconds buys about 20 words of reading. The visitor is judging the page as an answer to whatever the link promised, and the judgment runs on the headline, the first line, and the general shape of the thing. Body copy barely participates.
For paid traffic the test tightens into message match. The ad made a promise. The page has ten seconds to visibly keep it. An ad about pricing that lands on a generic homepage fails the audition before the hero image finishes loading, and you paid for the ticket.
The check costs nothing. Open your landing page, count to ten, close it, and write down what it offered. If your summary does not contain the thing the ad sold, you have found where the conversion rate went.