You can adjust the amount of traffic that SiteSpect assigns to a Campaign by changing its Frequency.
Frequency allows you to control the probability that a visitor is assigned to a Campaign. Frequency is a probability between 0 and 100. This setting does not control a percentage of traffic diverted to a specific Campaign, but only the probability that an eligible visitor will be assigned to the Campaign.
For example, if you are running a single campaign with the Frequency set to 50%, all visitors to your site (assuming they meet any Audiences) have a 50% probability that they will be assigned to this Campaign. So 1 in every 2 visitors will be assigned to the Campaign and the unassigned visitors will be eligible for another Campaign or remain unassigned.
If you have a Campaign that is assigning visitors too quickly, you can down-weight the Frequency to allow SiteSpect to assign visitors more slowly and run the Campaign over a longer period of time.
You may prevent an active Campaign from accepting any new assignments by setting its Frequency to 0%.