Now you can limit your traffic by time, by impressions per hour / per day / total.
To do so, go to Ad campaigns page and either choose a current ad campaign or create the new one. Click on the Edit button.
Click “Show/hide advanced settings” button at the page bottom.
The Limits section allow you to limit your traffic:
By date. Let’s say you’ve arranged to sell your traffic to some direct buyer during one week. You can choose the start and end date here.
By impressions per hour. For instance, if you want to send 10 000 of hits to another website per hour.
By impressions per day. For instance, if you’ve sold 1 000 000 of hits per day to some advertiser.
By total impressions.
Don't forget to save all the changes once you are finished with these settings!