Don’t let Black Friday turn into blackout Friday – five top tips for e-commerce success from Varnish Software

Black Friday – the mere utterance of these words can either make excited shoppers froth at the mouth or send shivers up the virtual spines of online brands who aren’t prepared for one of the busiest shopping days of the year. Lars Larsson, CEO of Varnish Software, explores how retailers can avoid making the ultimate e-commerce faux-pas to maximise the Black Friday opportunity for another year

In 2018, frustrated shoppers flocked to social media platforms to unleash their outrage. Why? The sheer chaos of Black Friday – so-called because of the calamities which occur on or around the day – had forced many UK retailers’ websites to crash. As reported by UK newspaper the Evening Standard, many sites were either displaying an error message as bargain-hunters attempted to virtually loot the internet, or brands rather annoyingly put avid shoppers in a queue. Yes, that’s online queuing. Might as well have popped to the high-street for a fist fight over a 50” TV after all. 

And so, in 2019 we wait with bated breath in anticipation of this year’s Black Friday event. It’s undoubtedly one of the busiest periods in the e-commerce calendar, providing retailers with an opportunity to steal a lead on the competition by ensuring the perfect mix of product availability, unbeatable bargains, speedy delivery times and a website that just works. And that’s exactly where retailers usually struggle to keep up with frantic demand – website performance. 

For a calendar event that can generate up to 30% of a retailer’s annual revenue, it quite literally can pay dividends for a retailer that’s ready and prepared. And if you can handle Black Friday, you can handle any other shopping event the year throws at you. With this in mind, here are our top five tips for ultimate e-commerce preparedness – for November, December, and all year round. 


It’s never too late – or too early – to start thinking about how you can create and implement a comprehensive plan for hardening up your website for Black Friday. While most retailers will stop making big changes in August to ensure stability in anticipation of one of the busiest shopping periods, it’s never the wrong time to think about how you can plan for the unpredictable. You never know when the Royal Family might set a new fashion trend. 


While trends and new technologies in e-commerce are advancing, it starts with the most basic requirement: your site has to work at scale and speed to attract, retain and satisfy your customers. To keep performance front of mind, retailers need to think about hardening their infrastructure to meet whatever traffic demands are thrown at it. If you’re not convinced that performance matters, then you might be surprised to hear that a 100ms delay can hurt conversion rates by up to 7%. On the flip side, every 1 second of page load improvement made to your site can boost conversions by 2%.

The general rule of thumb for any retailer is Black Friday web traffic should equate to about four or five times the normal web traffic. Speed is directly correlated to conversions, so the more you can speed up your site, the better you will fare on Black Friday. Overloads will lead to severe slowdown and potential crashes, meaning a competitor will come and snap up your portion of the Black Friday pie. 


To protect the performance and power of a website, there are a number of tools and techniques that retailers need to consider in order to maintain a customer experience worthy of a Black Friday behemoth:

  • High availability: Keep your site up under all levels of traffic demand and protect your origin.
  • Smart caching: Caching relates to the temporary storing of content (such as specific web pages or images of products) so that it can be retrieved more quickly once the request to view the content is made again. Employ smart caching and cache invalidation strategies to ensure speed and delivery of the freshest content.
  • Security: This is understandably a major concern for both retailers and consumers. The number of data breaches and e-commerce ‘hijackings’ making front-page headlines has created greater awareness and consumer demand for better, more robust security measures. Tools such as encryption, to ensure your entire cache is encrypted, and request inspection and throttling for the prevention of DDoS attacks, can ensure the website is up and running as you’d expect it to be.


After you’ve implemented any changes or new tools to help boost uptime during peak traffic times such as Black Friday, test your site. Test, test and test some more. Find out what kind of load your site can handle. Run a number of different scenarios at once, thinking of all potential customer journeys and the most popular ones. Performance testing requires planning and predictive ‘foreseeing’ of multiple possible scenarios and outcomes to provision adequate, real-world condition peak stress testing. The more you can anticipate, the more you can plan for the unexpected. 


What separates the best retailers from the not so good is the ability to match and predict the upcoming demands of consumers. Heavy use of data analytics and predictive data modelling yields insights that help retailers understand and better serve shoppers. 

One way to do this is by deploying ‘predictive browsing.’ By gathering traffic data and user-behaviour analysis, retailers can predict and pre-browse on a user’s behalf and get content ready before he/she has requested it. In theory, this should eliminate any waiting, and when the prediction is correct, enhance website performance. 

Adobe Analytics data estimated that 110.6 billion USD was spent by December 19, 2018, which is an increase of 17.8% year on year. Black Friday and the shopping period that surrounds it can be a very lucrative time for those willing to put in the work before the sales hit. Unfortunately, many major retailers learn the hard way each year that it’s essential to get these five factors right, or disaster will strike. Unfortunately, we sometimes see repeat offenders year after year. But with a huge slice of revenue up for grabs, by implementing some simple tools and technologies to boost the performance of their websites, retailers can narrow the gap between competitors and maximise the Black Friday opportunity, without margins taking a huge hit. It’s a no brainer.