Cross domain tracking in Google Analytics is a way to track a visit on multiple domains within a single session.
GA uses a client id to assemble sessions from individual pageviews; all pageviews and other interactions within a certain timeframe that share a clientid are part of one session. HTTP is a stateless protocol, meaning that individuals hits are not connected to each other. So GA persists an id within the “_ga” cookie on the client and sends it to the Analytics server with every tracking call. Cookies are domain specific, to if a single web property uses multiple domains the client id is lost as the cookie itself cannot be transferred between domains. So GA uses a workaround to overcome that particular problem.
» Read Cross Domain Tracking with Clean Urls
Google has announced that they have introduced property moving, i.e. you can now take a tracking property in a GA account and shove it into another account. This is somewhat nice for many people (if they have mis-organzied your account, or if their various businesses split) , but it is extremely nice for agencies with GA… ( Read GA Property Moving)
» Read GA Property Moving
Google has updated GTM and Simo Ahava has covered this so thoroughly that there is not really much point for me in writing an article myself. More importantly Google has adopted the new European privacy framework.
» Read Google adopts privacy shield, GTM updates
Another (off-topic post) on stackoverflow.com asks: I need to filter out some URI from Google Analytics (beucase I send some custom pageviews on these pages instead), but not the events sent together on these pages.
» Read Google Analytics: Filtering URI But Not Events Sent Together
Google has announced that Google Data Studio, the report builder that was announced as part of Google 360, will be available for free.
» Read Google Data Studio available for free (US only)