Black Friday e-commerce readiness checklist


You may be thinking that Black Friday is ages away but, believe me, it will come round sooner than you think and businesses should really start preparing for it now.  In the UK, Black Friday is not just a day any more. It is at least a week; normally starting on the Tuesday before and ending on Cyber Monday (the following Monday). I have seen many retailers then extend it by a further day to a full 8 days of heavy promotion.

This period can make or break a year for a retailer. We have clients that will take up to £10m of online orders over this period which is a significant percentage of their annual online revenue.  Getting black Friday right can pay huge dividends for a retailer whereas getting it wrong can be a very costly mistake.

Being a veteran of a number of Black Fridays, and the bearing some of the scars, I have seen both successes and failures so here is my Black Friday readiness checklist for retailers:


Over Black Friday, a website is likely to see a huge spike in sustained traffic; often 4-5 times the usual level. A website running slowly can have a big impact on conversion rate but peak traffic at this time has the potential to completely take a website down. A web platform can very quickly become overloaded and go from fast and performant to offline in a very short space of time. There is often a very small window in between. There have been plenty of instances of the websites of large retailers, such as Currys PC World, Argos and John Lewis that have gone down or had serious issues on Black Friday over the last few years. This will have resulted in many millions of lost sales and the associated cost of that.

It is vitally important that you test your web platform’s performance well in advance of Black Friday to give you enough time to fix any issues you find. Performance of a web platform does not tend to degrade in a linear way; it simply goes from fast to down in a very short space of time. This often is because the front end servers or the database become overloaded and everything cascades very quickly. You can think of it as a bit like a bucket over flowing or a pipe that is too small for the flow of water. Once capacity is reached, everything starts to overflow.

Performance testing can be complex and costly and you will ideally use a third party performance testing company like NCC Group to manage this for you. You can do it yourself by writing tests using a tool such as Jmeter and then running them through a service such as Blazemeter. Although this is a much more hands-on and technical approach than using a specialist company, you can still get some great benefit from it at a much lower cost. This is not an exact science and running tests that mimic real users is very challenging. You will need to run 3-4 different scenarios at once, including different checkout journeys (delivery/click and collect) as well as standard browsing. You need to think of the journeys through your websites that are likely to put the most load onto your platform and ensure that those are proportionally represented in your test scenarios.

The profile of traffic during this period is not what you would see throughout a normal day. On days like this traffic is very spiky starting from around 06:00. Because performance testing is not an exact science it is advised that you ensure that your tests achieve at least twice the amount of traffic and orders you expect to receive during Black Friday to give you enough margin for error and to counter the fact that you will never be able to truly mimic real user behavior.

Code freeze

E-commerce rarely stands still so it is likely that you have a constant development roadmap for your website. It is tempting to continue releasing code to your platform right up until the day to ensure that you have the best functionality available. However, the closer you get to the period, the more risky a deployment becomes. Generally speaking, you should not be deploying code in November unless it is critical to do so. This will give you a few weeks to find any bugs or issues. The last thing you want is a critical issue that could impact the sales on these days.

You also need to consider that your performance testing may find some issues that you need time to resolve. You should ideally carry out your performance testing after your code freeze so you need to make sure that there is a big enough window.


Security is always important but never more so than during this period. Periods of high traffic are the perfect time to try to hack a website. During this time your website will be inundated with requests and it will be much harder to spot and react to malicious traffic events as they will be well camouflaged in amongst the elevated traffic that you now have. Your focus will be on trading your website on that crucial day and you will be slower to spot or react to security issues.

Make sure that you carry out regular penetration tests on your platform (at least every 6 months) and ideally use an application security testing tool such as Nessus on a regular basis.

Dispatch and delivery

Are you set up to cope with the huge spike in orders that you can expect during this time? Can your order management and dispatch processes and systems cope with 5 times the normal number of orders? You may need to draft additional staff into your warehouse for a week around this time. The last thing you want is to upset customers by delivering late.

Can your delivery partner cope in the days after Black Friday? Your customers are not really going to care whose fault it is if their orders are delivered late. Make sure you ask them about their capacity during this period. There have been cases in the past where a courier company has imploded in the days after Black Friday letting lots of customers down.


You can expect quite a spike in returns after Black Friday. Customers tend to get a bit carried away at this time and are likely to make a few rash purchases. Although there is little you can do to stop this, you will need to plan for a lot more returns than normal in the weeks following Black Friday. You are likely to be busy gearing up for Christmas but it is important to still manage customer expectations post sale.

Customer services

You can expect an influx of customer service queries on this day. Everything from reports of promotion codes not working through to questions about products and stores. You should consider increasing your customer services capacity before and immediately after this period.

Performance of 3rd party systems

Most e-commerce websites will rely on multiple 3rd party services to function. These may be postcode lookups, payment gateways, search merchandising providers or reviews. During the Black Friday period, these services are under a lot of load and I have seen them take big websites down in the past. You can spend a lot of time ensuring your web platform can perform well under load only for it to be crippled by a critical 3rd party service that can’t cope. Before Black Friday, ensure that you have audited your 3rd party services and asked them about their plans for this period. Ideally you will de-couple your platform from these services so that your website can still function when they are down.  However, this may not be possible. Last year we had a client whose 3rd party postcode lookup service went down on Black Friday. When they called the provider’s support line, the technician didn’t even know that it was Black Friday.


What is your competition doing over this period? Everyone is competing for the same customers on this day and you may not want to be the only one in your peer group that has not joined in. Maybe you have only planned to participate on the actual day whereas your competition is discounting over the entire week. Do your research and look at what your competitors did last year as they are likely to repeat it this time.


This is a very tricky thing to get right. The discount needs to be attractive but it will hit your margins. You don’t want to be discounting much less than your competitors but you don’t want to give away margin unnecessarily.  In the UK, we tend to see discounts of between 20% and 30% normally on full-priced items only. Some retailers will also offer free shipping. Often a retailer will offer a lower discount from the Tuesday before and then an additional discount on the Friday itself.

In store

Let’s not forget, Black Friday is not just about online. We all remember pictures of people fighting over cheap TVs in supermarkets a few years ago. We now live in an omni-channel world where consumers do not view retailers in silos. They expect to be able bounce seamlessly between different channels and have the same experience however they interact with you. Your customers will expect your Black Friday discounts to be the same online and in store so it is important that you co-ordinate your different channels.

Branwell Moffat
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Branwell Moffat

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