Just how much of your Web behavior is actually tracked by data aggregators? Well, Google and its affiliates alone track visitor identities on nearly two-thirds (64.4%) of worldwide Web browsing, according to a study by anti-tracking vendor Ghostery. Facebook trailed with trackers for a mere 28.8% of all page visits. Ghostery found 77.4% of pages had at least one tracker while more than 15% of pages had ten or more.

Here’s an alliance between data vendors. Time Inc.-owned Viant, which has an advertising audience database of 1.2 billion registered users, is adding information from retail data aggregator IRI. Marketers will get a clearer picture of advertising results at fine levels of detail, although not tied to identified individuals.

GrowthLoop will use TransUnion identity data to improve U.S. consumer match rates on client files sent to advertising media such as Facebook and Google Ads.  The data should also help clients to find matches among records within their files, building more accurate customer profiles.  GrowthLoop calls itself a “composable CDP”, meaning it works with data assembled in external data warehouses.