When it comes right down to it, page-load speed is one of the biggest factors of getting a viewer to read your pages. If you think about it, it makes sense. If your pages load slowly, your viewers will leave. It isn't rocket science.
Page load speed is a huge factor for big-name brands like Google, Facebook, and Amazon. They think about the big picture, where a fast page load actually saves them money.
Let's think about it from the perspectives of Google, Facebook, and Amazon. One of the biggest costs of keeping the sites up is the hardware. It takes hundreds, if not thousands, of machines to serve pages to their users. If servers can spend less time serving pages, it would mean that they need less of them to do the work.
Page-load speed is so important that Google even made it a factor in their ranking algorithm. If your page takes a long time to download, you're wasting Google's robot's time. You're also wasting viewer's time. And even your own time. Not to mention that your viewers will just click away because they were tired of waiting.
So, how do they save time?
One of the ways they do it is to optimize requests. One of the most overlooked parts of serving a page is the number of individual pieces it takes to make the page.
Think about the smaller parts of a page. Even the most minimal page has HTML, style sheets, scripts, and images. For each one of those elements, a browser requests the element by establishing an individual connection. When the element has finished downloading, the connection is closed and another one is established. The process is done over and over until the page has finished downloading. Old browsers download pages at one or two elements at a time. Newer browsers allow between four and eight concurrent connections at a time. So, you can imagine, a page that has more than thirty elements will begin taking more elapsed time.
In fact, browsers spend between 62% and 95% of the page-load making those connections. 5% to 38% percent of the time is spent downloading the elements after the connection is made. Did you notice that the page connections take more time than downloading the elements?
There are a lot of ways to increase page-load speeds. This is just one of those ways. In another post, I'll talk about other ways for improving efficiency.