Our statistics show that the campaigns that fail are those that start slowly. On the contrary, campaigns that have a good start are less likely to fail.
Faced with this observation, we allocate by default the clicks to the campaigns with the slowest progress, in order to significantly reduce the number of failed campaigns.
However, if you wish to allocate your click to a particular campaign, you can click on the cogwheel (top right) before making your click in order to choose which campaign it will be credited to.
Similarly, you can choose to assign your clicks by default to the campaign whose end is closest in time if you wish.