Ad longevity

Ad longevity is the number of days an ad has been active. Public ad libraries show when an ad started running, so anyone can work it out, and RivalSonar shows it as active days on every ad.

The logic is simple. Advertisers pay for every day an ad runs. Most ads are tests, and losing tests are switched off within days. An ad that is still live after several weeks is likely paying for itself, or at least the advertiser believes it is.

Read it with care:

• Long-running does not always mean high spend. Some ads run for months on a tiny budget.
• Some advertisers forget to switch ads off, especially small stores.
• New ads look weak by default. A three-day-old ad may be tomorrow's winner, so look for many variations or growing reach.
• Copies of the same creative with different start dates may mean the advertiser is scaling by duplication.

Longevity is strongest when combined with other signals, such as rising reach, several stores running the same product and rising estimated orders. The guide on reading ad longevity and reach gives a full method.