A Sticky Campaign is several messages deployed at different times using the same list with all tracking and reporting over time grouped to a single Campaign. Most Campaigns are unique with resulting events reported based on time deployed; however when a List has Sticky Campaign enabled, the resulting tracking data is grouped for reporting.
Sticky Campaign Use
If you are using a single list for normal everyday campaigns in addition to occasional one-off messages, do not use Sticky Campaigns. Instead, two separate lists are recommended: one that the subscriber is added to when they opt-in to receive normal messages and one to send one-off welcome/transaction type messages. The welcome/transaction list would then only be used for those occasional messages and not to send other business campaigns.
Sticky Campaign can be disabled at anytime in releases prior to v12.09.0. This may result in confusion with reporting, and is not recommended. Instead, it would be better to create a new list with Sticky Campaign not enabled, transfer the subscribers (export from old list, then import to new list), then archive the old list.
Sticky Campaign Alternative
At one time, Sticky Campaigns was a very useful feature, but is more often unnecessary since the addition of Automation.
In the past Sticky Campaign was recommended to keep tracking information for a List together. A typical use was in the delivery and tracking of recurring Welcome messages for new subscribers. With the Sticky Campaigns option enabled, new subscribers were sent a personalized welcome message, encouraging them to sign up for other lists, shop your site, or use a coupon, and the results were tracked over time. However, Automation makes it easier to launch and track Welcome messages and follow up campaigns.
Sticky Campaign and APIs
Sticky Campaign was also required in the past for API one-off messages, such as notifications for unique events, like purchases. API one-off messaged would not process bounces or track for reporting without the option enabled.
This requirement has changed since 11.0.0. You can now group Send and SubandSend messages into campaign using the Campaign Name argument instead, and the Subscriber ID Tag used for processing bounces is automatically added without the Campaign requirement. (See documentation for your preferred API for more information.)
Sticky Campaign Now
As of v12.09.0, once a List with Sticky Campaigns enabled has been deployed, the List cannot be edited to turn off Sticky Campaign. As a result, in v12.10.0, you are able to see each separate deployment to a Sticky Campaign List as a unique instance in the Campaigns list. In order to do this, however, you must contact your Account Manager to request the feature, which is enabled at the Account level.