The lesser-spotted Slow Tail


Jakob Nielsen spots another-shaped Tail, this time the lesser-spotted Slow Tail, referring to the conversion time for buyers to complete a transaction after their initial visit to a website:



"A full 5% of orders occur more than four weeks after users click on search engine ads.



...Although 75% of the conversions occurred within 24 hours, the last quarter took much longer to arrive. Orders didn't reach the 90% mark until 12 days after users had clicked on the advertisement, and it took four weeks to reach 95%. Thus, the last 5% of orders happened more than four weeks after the initial click.

The following chart shows the days required to reach a certain percentage of the ultimate conversions."

  Percentile chart showing delay in orders, especially for the last 20% of sales (after the 80th percentile).


Via Lawrence Lee.

Comments (1)
  1. Steve says:

    Its interesting to review this data wrt. affiliate programs such as e.g. Amazon Associates which generally only credit activity within 24hrs of 1st referral.

Comments are closed.

Skip to main content