If you install a surveillance camera in your retail store, you need to clearly educate the clientele about its use.
A surveillance camera is a good analogy to analytics software on your website.
However, the camera in the store is more for crime prevention. After all, you don't watch the movies every night and then write down which visitor was in the store for how long or which product they looked at for how long.
A website visitor analysis is more critical, because you follow the visitor in fact at “every turn” and record every action on the website and save this over a longer period of time, honestly: without any valid reason.
For this reason, you need to give the visitor the option to opt out of this tracking.