Appnext platform will pause a campaign when it reaches 90% of the target daily budget.
As late conversions can happen after this point (for example a user clicked on the ad, downloaded the app, but only opened it a few hours later, or your attribution company reported the install only after a few hours), a learning mechanism will then kick-in and will start pausing the campaign at an earlier point in the following days.
Since all billing is based on actual installs and not clicks, even though we have placed the learning mechanism it can never assure that in all cases the target daily budget will be met.
What should you do as an advertiser to minimize over spend? Please take close care of actual daily spend, lower the budget if needed or pause if the actual daily spend is too high.