1. A method comprising: determining, by a computer-based system, a first group of customers for an ad impression; selecting, by the computer-based system and based on the determining, a second group of customers based on look alike modeling of the first group of customers, wherein a first customer is part of the second group of customers; creating, by the computer-based system, a tag that includes a campaign request by a merchant, wherein the campaign request indicates the ad impression for the first customer based on the tag; further creating, by the computer-based system, the tag with additional instructions that cause, upon a web client navigating to a website, a cookie to be transmitted from the web client to the media buyer system to indicate that the first customer is online such that the media buyer system purchases the ad impression that is sent to the first customer; tagging, by the computer-based system, the cookie with the tag that includes the campaign request for the first customer; anonymizing, by the computer-based system, the cookie to create an anonymized cookie by stripping the personal information (PII) that is associated with a first customer; installing, by the computer-based system, the anonymized cookie on the web client associated with the first customer; receiving, by the computer-based system, data from the anonymized cookie; modifying, by the computer-based system, the tag associated with the cookie to at least one of: associate or disassociate the first customer with at least one of: a category or type of the ad impression; selecting, by the computer-based system, the ad impression from the at least one of: the category or the type of the ad impression; transmitting, by the computer-based system, the ad impression to the web client associated with the first customer; identifying, by the computer-based system, a first expenditure associated with the first customer that received the ad impression; comparing, by the computer-based system, the first expenditure to a second expenditure associated with a second customer that did not receive the ad impression based on the campaign request but fits parameters associated with the campaign request; and generating, by the computer-based system, a report showing the results of the comparing.