Between managing last minute designs to client deadlines, it's stressful enough keeping ahead of your product launch. In my personal experience of building, launching and exiting close to 15 businesses here are a few things I've learned that will almost always make your product launch fail.
Not Anticipating Time Off By Employees
This echoes the wider advice of listening to your employees and creating a workplace standard wherein your staff feels comfortable sharing personal things with you, particularly when they relate to their expected performance and attendance at work.
Moreover, in a time where freelancers make up close to 70% of a typical organization's workforce knowing what dates are public holidays in your freelancer's country will help you better plan the date of release for your product or a major update, or other times when you believe your company may need the extra manpower.
Under/Overestimating Expected Demand on Launch Date
Like many of us, your family probably preached about how you should maintain a budget, balance your checkbook and keep track of your finances. Yet, like a big proportion of us (including me), you still failed to do it.
And that's alright because what may work for you may not work for somebody else, whom might be better at keeping a small spreadsheet of their incomings and outgoings.
That said, not correctly estimating the amount of expected demand your product is likely to receive leading up to and on launch day can really mess up your supply chain and advertising spend. This doesn't apply as much in the case of digital items where supply is generally unlimited.
However, for physical goods that require importing, manufacturing and shipping it's every company's worst nightmare to have just purchased a truckload of items in anticipation for a big launch, and then come launch day that falling through and their business is left with a plethora of excess stock.
Likewise, though perhaps not as severe is when launch date orders exceed your expectations and you can't deliver enough product in time so you end up missing out on a potential big sum of revenue.
Note: It might also be worth telling your payment processor about your launch date and expected revenues because I learned the hard way back in 2010 when I was using PayPal to collect payments.
I was selling a Yahoo Answers suite of digital marketing tools that would help automate lead generation. Launch day arrived and to my excitement, we took in a larger number of orders and therefore had an influx of money hit my PayPal account.
For one reason or another (to say nothing ill of PayPal), PayPal thought something was amiss about all of this money and proceeded to cancel my account. It was only a year later that I managed to finally withdraw that income. Not too mention, I had to forego plenty of further orders while looking for another payment processor and felt bad about not being to pay my developers on time.
Had I notified PayPal in advance about our expected revenue on launch date perhaps that wouldn't have flagged my account as suspicious and keep everything running normally.
Miscommunication Between Your Engineering, Product & Marketing Teams
Although some companies like Apple are notoriously known for promoting secrecy between different departments, for smaller businesses it is imperative that you as the CEO promote a free flow of information between these teams.
Otherwise, a lack of information typically leads to miscommunication as employees try to interpret things themselves and as you would expect quite a few things end up getting lost in translation (especially if employees are inadvertently fabricating information to appease their managers and higher ups).
Generally, this happens because people in different departments may value different things. For example, whilst engineers and programmers may want to fix bugs, and improve the product at all costs. The product based teams may simply want their latest iterations to be functioning well and on time, whereas the marketing/sales teams may be looking to sell whatever they can to attract new customers.
All of these things can result in products not being ready to release on time, or releasing with incomplete features and excess resources being dedicated to launch date marketing expenses which ultimately prove wasteful.
Note: These are rough and generalized examples. I'm not trying to suggest that one department is superior to another, or that they don't all want to achieve a common goal (though getting all teams working towards a unified goal takes work). Simply, what may happen when there is a breakdown in communication.
In conclusion, be it not listening to your employees, or not calculating realistic revenue expectations, or even failing to promote a good flow of information between teams to ensure deadlines are met, and products are released to their full advertised specifications - a combination of one or more of these things will make your product launch fail.