Campaigns can be momentarily paused for a number of reasons. The two most common are due to the number of contacts and the callback interval.
The callback interval is the amount of time that needs to pass before we call a lead back. This is why some campaigns show they have contacts left to call but for some reason are now allowing any calls. It's because all the contacts have been called at least once and the not enough time has passed since the last attempt to contact the leads. As the callback interval elapses, you'll be able to call again. This is also why you may see a campaign open up for just a few minutes or a few hours and then abruptly pause again.
Here's an example:
Campaign A has 2 contacts. We called them at the following times:
Contact A: 3 pm
Contact B: 3:15 pm
After the first contact, we have to wait until the callback interval has passed before trying them again.
If the campaigner sets their callback interval to something low like 30 minutes, then calls will open up much sooner for that campaign; however, if the callback interval is set to a longer period of time like a few hours or days, it may increase the chances that a campaign pauses.
Here's an example:
Campaign A has 2 contacts. The callback interval is 1 hour. We called them at the following times:
Contact A: 3 pm. At 4 pm we'll call contact A again.
Contact B: 3:15 pm. At 4:15 pm we'll call contact B again.
Campaigns with a low number of contacts and a high number of Upcallers will have more frequent pauses than a campaign with high number of contacts relative to the number of Upcallers.
Campaigns with a high number of contacts and a low number of Upcallers will have more consistent calling work for Upcallers.
Related article: Is there a limit to the number of campaigns I can join?
If a campaign pauses, depending on the reason it's pause, it may not show up on your list of campaigns under the My Campaigns dashboard. Once the campaign is live again, you'll see it back on your dashboard.
Remember, if you didn't get a notification saying the Campaigner removed you from the campaign, you're still on it. The Campaigner may have just taken down the campaign to make some adjustments to it.
Another reason campaigns pause is because their budget (credits in their account) are running low. You'll see a "be back soon" message on the campaign. As soon as the Campaigner adds more funds to their account, the campaign will come back.