1. A computer-implemented method comprising: receiving, by a processor, first unique visit interaction data representing interactions with a first entity by a first visitor and second unique visit interaction data representing interactions with a second entity by a second visitor; aggregating, by the processor, the first unique visit interaction data with the second unique visit interaction data to produce first unified visit interaction data; computing, by the processor using a first visitor stitching algorithm, a first unified visitor level of certainty that the first visitor and the second visitor are the same visitor; and generating, by the processor, a report using: the first unified visit interaction data while a user-specified level of certainty is less than or equal to the first unified visitor level of certainty; and each of the first and second unique visit interaction data while the user-specified level of certainty is greater than the first unified visitor level of certainty.