Our new Campaign Throttling allows you to limit campaign's traffic speed by percentage. For example, if you choose 30% it means that your campaign will use only 30% of its visibility potential. You may find this useful, for example, when testing new offers as it allow you to better control your budget. You can access the throttling by selecting the Throttling icon in under the Status section of your campaign.
Be advised though that lowering the throttling will surely set limits on the traffic that you will get, so after testing - don't forget to set it back to 100%.
We are also using the throttling internally to control new campaigns - during the first few hours after any new campaign is uploaded, its throttling is controlled by the system, mainly for quality assurance reasons. After this short time-frame - the throttling is set to either 100% or to any value set by you.