1. A method comprising: identifying, via a processor, a first set of data from a first data source, the first set of data different from a second set of data from a second data source; generating, via the processor, a third set of data based on the second set of data from the second data source; generating, via the processor, a model based on a difference between the first set of data and the third set of data; applying, via the processor, the model to the first set of data; and assigning, via the processor, viewership to an impression associated with the first set of data by imputing viewership associated with the second set of data to the first set of data.