What is a Data Aggregator?

What is a data aggregator? They are companies that collect and share business data with online directories like Google, Bing, and Yellowpages. They typically build their business databases by scanning and transcribing things like phone records, utility records, business registration websites, and printed Yellowpages directories.
There are 4 primary data aggregators in the United States: Neustar, Acxiom, Infogroup and Factual. Moz created a local search ecosystem chart which shows how the data aggregators and online directories interact with each other to build and power online listings for businesses across the web:
You can learn more about this ecosystem by visiting Moz’s original post about The U.S. Local Search Ecosystem