Once you have tracking code in the client the temptation to use it to answer problems will be very tempting, and the pressure from other stakeholders to add 'us

Once you have tracking code in the client the temptation to use it to answer problems will be very tempting, and the pressure from other stakeholders to add 'useful' data will pile on. If your product manager wants to know user screen resolutions it's much harder for them to argue "We track nothing, we need to implement tracking to get screen resolutions." than it is for them to say "We already track loading times; it's a few additional lines of code to add screen resolutions".