The forecast is a useful tool. It is calculating on the basis of the statistical data from the last 30 days, which view- / click numbers could be achieved for a certain period, channel and / or format.
Please note that the calculation of the forecast is based exclusively on historical data - the calculated values are only exactly occur when all the positions stay the same (that means all websites deliver exactly the same quantities, etc.). Please also note that other ongoing campaigns could access to the calculated volume. This means that depending on the workload with other campaigns just a part of the calculated volume would be available. The calculation of the forecast can therefore only be a very rough estimate of the maximum deliverable quantity by constant framework conditions.