Any web page that takes more than just two seconds to load could be deemed slow. Apart from being annoying to users what adverse effects can this have, what causes it, and how can it be rectified?
If your website is slow to load it will not be as effective, it really is that simple. This because search engines will not rate you as highly in their rankings  so you’ll receive less traffic; and users will get frustrated, and so you’ll convert less of them in to customers.
“40% of mobile shoppers will abandon an e-commerce site that doesn’t load in 3 seconds” 
The speed that a web page should be delivered depends on a lot of factors including the complexity of the site as a whole, but generally speaking a site is considered to be slow if the load times are more than a couple of seconds.
“2 seconds is the threshold for eCommerce website acceptability. At Google we aim for under half a second” 
Maile Ohye, Google
Slow load times are typically caused by slow or misconfigured servers (including shared-servers), complex or inflated content management systems (such as WordPress, Joomla or Magento), high site traffic, or poorly optimised front or back end code.
Some of these can be easy to fix; websites can be moved to faster servers and code can be optimised front-end by, for example, merging lots of smaller files in to one larger one. Web developers can also tweak the internal system caching commonly used database queries, or rewriting parts of the code to be more efficient.
Other causes may be harder to fix; for example if a website is running a complex system such as Magento or to some degree WordPress, it has a lot to do just to get by run day-by-day. There are always infrastructures to change and modules to install that can get the page load time down to something sensible, but this can be a more time-consuming job.
A lot of web developers focus solely on the underlying system and database, but there is in fact a lot of merit speeding things up front-end where possible too; this is where there’s a lot of potential for improvement , and it can be less costly to do.
“Almost half of consumers expect a page to load in 2 seconds or less” 
So is it really worth it? The short answer is yes users are impatient and speed matters, it matters a lot.
This is one of the things we can do at Webbed Feet UK, we can reduce your page load times on all websites from the large and complex, to online shops, to smaller ones. We have software that not only tells us your page load times, but can tell us which specific elements are causing the problem and therefore where the bottleneck is.
You can easily test the speed of your own website, see how it compares to others, and see how it can be improved here:
… and if it’s more than 2 seconds, get in touch and we can help.
(for anyone who’s interested, I just tested our home page at 1.46 seconds, but it does vary)