These kinds of stories don't get made into blog posts because they don't help sell any kind of narrative. Novice eCommerce store owners will focus on the "top 10 things you can do to increase conversion" from blogs like the one mentioned above.

At a large scale page load time would have a discernible impact on your bottom line, but for most it is a premature optimization (as long as you aren't trying to deliver 10mb webpages).