In around 8 years of web development, mostly focused on consulting and focusing on ecommerce, I've never seen a net gain from using analytics on a site. If the end goal is to produce data for the sake of data, well sure that will work. Rarely does anyone analyze the data though, and I've never seen anyone dig into the validity of the data and ensure that Google Analytics is in fact accurate and reliable for them.
One of the most disappointing client experiences I had was after building a custom shop for a company that was heavily focused on graphic art. We optimized the hell out of their site, getting performance scores of 97+ when every page was image heavy and included a product grid designed for a masonry grid look similar to Pinterest.
A few days before launch they asked us to add their Google Pixel script. The next day they had included 7 or 8 different third party scripts and blown performance scores into the mid 50s. Its their site and they can do what they want with it, but I sure could have saved a lot of dev time if performance didn't matter at all.
One of the most disappointing client experiences I had was after building a custom shop for a company that was heavily focused on graphic art. We optimized the hell out of their site, getting performance scores of 97+ when every page was image heavy and included a product grid designed for a masonry grid look similar to Pinterest.
A few days before launch they asked us to add their Google Pixel script. The next day they had included 7 or 8 different third party scripts and blown performance scores into the mid 50s. Its their site and they can do what they want with it, but I sure could have saved a lot of dev time if performance didn't matter at all.