UTM parameters

Labels added to the end of a web address that tell an analytics tool where a visitor came from. The letters stand for Urchin Tracking Module, after Urchin, the analytics software Google bought in 2005 and turned into Google Analytics. The three main labels name the source that sent the visitor, the medium, which is the kind of channel, and the campaign. Optional labels add the keyword or the version of an ad. The labels are set when the web address is prepared, by a person or by the email or advertising software that sends the address out. When a visitor clicks the address, the labels arrive with it, and the analytics tool records the visit under them. Some visits reach a site with no record of where they came from, and the labels supply that record. An analytics tool that treats capital and small letters as different characters counts one source written in two ways as two sources.