Global  e-commerce sales will soar past $1 trillion this year, with more of us than ever before turning to our tablets, smartphones and computers to buy almost everything we need. 

Yet despite the fact that that the online retail marketplace is now incredibly mature, there are common mistakes that plague huge numbers of e-commerce websites including global brands and local startups alike. 

Simple mistakes on your e-commerce website could be the difference between selling and sending your visitors running to your competitors. Here are some of the e-commerce errors that could be costing you your share of $1 trillion this year.

1. Failing Mobile Users

30 percent of online retail purchases now take place on mobile. But even as recently as April 2015, almost half of Fortune 500 sites were not mobile ready and the majority of small business sites were failing at catering to mobile users too.

Google's mobile results are increasingly featuring fewer and fewer non-mobile websites and we're steadily seeing more sites cater to mobile users. But many e-commerce businesses still offer up poor mobile experiences.

The solution? Analyze the devices driving your users and sales, look for barriers to conversion for mobile users and optimize their experience.

2. Templates

Custom e-commerce design can run into the multiple thousands of dollars, which is why themes and templates are a popular option for small online retailers. But Kevin Jones, Founder of e-commerce platform, Shopblocks, believes templates cost sales:

"Templates and themes strip an e-commerce business of any unique brand or personality. Take a popular Shopify theme like Cogify and you'll find loads of websites using it. Some of them sell soap, some sell photo prints and some sell clothing but they all look and feel the same. It's inauthentic. 

How can one theme be as effective at selling soap as at selling clothing? Users buying these items need different information to make their buying decisions and themes simply don't allow you to build your site around your products. This is why we invented BlockLab - to enable online retailers to easily build a custom online shop around their products without a template, developer or designer."

3. Slow Websites

Slow site speeds kill conversion rates. 

Amazon data from 2006 showed that every 100 millisecond delay in loading cost the company a 1 percent loss of sales. And in 2009, Forrester Research found that 47 percent of users expect a web page to load in 2 seconds or less.

The Obama for America election campaign credits an increase in page speed with a 14 percent uplift in donations.

Your customers expect your site to be quick on any device. Slow speeds cost sales.

Tools like Google's Page Speed Insights and GTMetrix are great starting points to establish any site speed issues you might have and begin to build a faster experience for your customers.

A Better Experience for Buyers

Your prospective customers are spoilt for choice in terms of where they can buy any given item from. So slow sites that offer poor mobile experiences and feel inauthentic simply won't cut it.

Online spend is surging and by improving the experience for your customers, you can increase your share of over $1 trillion.