Patent attributes
Methods and apparatus are disclosed to monitory online activity. An example method includes collecting first uniform resource locators from a first client device having a meter. The example method also includes collecting second uniform resource locators from a second client device not having a meter. The example method also includes determining that ones of the second uniform resource locators from the second client device correspond to online activity of a user associated with the first client device based on ones of the first uniform resource locators matching at least portions of the ones of the second uniform resource locators. Additionally, the example method includes associating the second client device with the user of the first client device.
