How fast a website loads is a BIG DEAL. Why? Because almost all websites are created to fulfill a purpose — like building brand awareness, making sales or capturing leads, etc — and anything that helps a website better fulfill its purpose (such as ensuring a site loads as quickly as possible) will be worth its weight in gold.
Just how influential is site speed? Well, it all depends on where on the scale of site speed your website currently falls. If your web pages are all loading within about 1 to 2 seconds (note: if you’re not sure how fast your site loads, have a good look at the free online tool called GTMetrix), you’ve almost certainly less to gain* by concentrating your efforts on further speeding things up than a website that loads in about 4 to 5 seconds: which will likely benefit enormously!
For the lowdown on exactly how site speed can affect your business, have a look at the following infographic — by WordPress web hosting experts WP Engine — that explains it all rather nicely.