What is lockWindow?

Introduced as one of Apple’s SKAdNetwork 4 (SKAN 4) features, lockWindow allows advertisers to lock the measurement/conversion window for each of the three postbacks. This means that instead of waiting for the measurement window to finish at its set time, you can choose to end it earlier.

On SKAN 3, there is only one 24-hour measurement window corresponding to one postback. For SKAN 4, lockWindow brings new opportunities for measurement customization and gives advertisers some control over when they want to receive a postback. Locking the measurement window at an earlier point does not necessarily mean you’ll receive the postback earlier, as the random timer length can vary drastically (particularly for Postback 2 and 3) but it does increase the chance of getting it earlier.

The image below shows that lockWindow was not used in the first measurement window and that a conversion was registered at the end of the 0-2 day time frame, triggering Postback 1 to be sent at a random time between 24-48 hours.

For measurement window two, however, lockWindow has been applied at around day five of the 3-7 day time frame, meaning that the conversion is locked and the timer for Postback 2 is triggered at that moment instead of at the end of the window. For measurement window 3, lockWindow is also not used.

Note that for Postback 2 and Postback 3 the postback will be sent at a random time of between 24-144 hours, compared to Postback 1, which will be received up to a maximum of 48 hours after the conversion is registered.

The key advantage of lockWindow is that it reduces the potential waiting time for a postback. On the other hand, it also limits the amount of information that can be extracted from each measurement window because—by design—it decreases the length of time that measurement is taking place. Also, for any inactive users, the lock won’t be applied, meaning datasets will be falsely skewed toward higher value users who are triggering events or are active in-app.

If you know that time post-install that the bulk of your users perform the key events you are aiming to measure, you’ve got a sweet spot that is perfect to lock the conversion and hopefully receive the postback sooner. This is likely most applicable in the first measurement window. For the other windows, you should know if the campaign is performing well or not and get as much information as possible by allowing measurement to take place for the full course of the window.

Until SKAN 4 industry adoption is more widespread, we recommend keeping your SKAN 4 measurement and testing a little more on the simple side. With this in mind, lockWindow could be implemented in a second phase of testing, once your fine and coarse conversion value strategies are in place.

For more information on iOS and SKAN measurement and how to implement a highly optimized conversion value strategy you can see our SKAN solutions, request a demo, or get in touch with your Adjust contact person.