5 Key Financial Projection Assumptions for Ecommerce Startups

June 6, 2022

Adam Hoeksema

In order to create reasonable financial projections for your eCommerce startup, there are several key assumptions that can have a dramatic impact on your revenue projections.  In this article I want to highlight 5 of the key assumptions that I see entrepreneurs struggle with most often.  Those 5 assumptions are:

  1. Average Cost per Click for eCommerce
  2. Average Conversion Rate of Website Visitor to Customer
  3. Average Order $ Amount for eCommerce
  4. Average Monthly Spend per Customer
  5. Average Customer Churn for eCommerce

Having unrealistic assumptions for these 5 key areas can easily drive completely unattainable financial projections and ultimately lead an entrepreneur to make poor choices in the business.  So in this article I am going to try to provide you some ranges, backed up by data, for these assumptions, and provide some real ecommerce startup revenue data that can help ground you to reality.  This data will help you determine whether your ecommerce startup is within the realm of what is reasonable.   I am also going to provide you with tools that you can use to do your own research on your industry, so that you can make the most informed assumptions possible. 

Lastly, before we get into it, you can find 3 very easy to use eCommerce financial templates that make it easy to use the 5 assumptions outlined in this article so you can quickly develop accurate and organized financial pro formas. And if you are needing to create a business plan for your ecommerce venture, check out this free ecommerce business plan template.

  1. Average Cost to Acquire a Customer for eCommerce

The average cost to acquire a customer for an ecommerce startup is really based on two key assumptions:

  1. What is the average cost per click to drive a visitor to your ecommerce website?
  2. What is the average conversion rate of website visitors to paying customers in ecommerce?

To determine the average cost per click for paid ads for your specific industry I suggest using the Google Adwords Keyword Planning Tool.  Set up a Google Adwords account and start to enter keywords that you would like to advertise for and Google will estimate the cost per click for each keyword.  This will give you a good starting point, and this is vitally important because the cost per click between two keywords can vary dramatically.  For example, “mortgage loan” has a cost per click range of $11.90 to $32.33; whereas, “mortgage rate” has a cost per click range of $1.64 to $6.24.  

Cost per click for – Mortgage Loan

google ad cost per click for mortgage loan example

Cost per click for – Mortgage Rate

google ad example of cost per click for mortgage rates

The reason these two similar keywords are so different is likely the intent of the search.  If you search for Mortgage Loan it probably means you are looking to secure a loan, so a bank or online mortgage lender can “sell” you a mortgage loan which has a high value, but with “mortgage rate” the searcher is probably just looking to see the current rates. 

If you plan to run ads on Facebook or different platforms, I would suggest following a similar process where you ought to be able to start setting up an ad account and get an idea of the cost per click based on your specific industry.  

  1. Ecommerce Conversion Rates

Your conversion rate for your ecommerce website can vary dramatically depending on a number of factors.  For example, the visitors purchase intent.  In our example above, someone that comes to your website looking for “mortgage loan” is probably going to have a higher conversion rate of completing a mortgage loan application when compared to a visitor that searched for “mortgage rates.”  

Even though conversion rates can vary dramatically, you can still get an idea of what a maximum conversion rate is likely to be, and make sure you keep your projected conversion rates below that level.  

According to Invesp, the average ecommerce conversion rate in the United States is 2.63%. 

Graphical user interface, text, applicationDescription automatically generated

I often see financial projections where the entrepreneur assumes conversion rates of 10%.  This simply shows that you don’t understand the ecommerce business.  It is incredibly unlikely that you will reach a 10% conversion rate, and it that conversion rate has a massive impact on your financial projections.  A conversion rate of 10% when it should really be 2.5% means you are overstating your revenue projections by 4x. 

  1. Average Order $ Amount for eCommerce

The next key assumption for eCommerce startups is the average order dollar amount.  Now you can’t really use an average ecommerce order amount for your specific business because you really need to take into account your industry specific details and your specific product prices.  

But if you are curious, Geckoboard estimates that the average value of an ecommerce order is $78. 

Graphical user interface, textDescription automatically generated

So as you develop your projections, I would suggest that you assume an average order that is $78 or less.  If you project over $78 per order, just be sure to have strong industry data to back up why that is a reasonable assumption. 

  1. Average Monthly Spend per Customer

The other key assumption that should also inform your average order value is the average monthly spend per customer.  For this data you need industry specific information.  For example, if you are selling dog food online, you can expect that your average monthly spend per customer shouldn’t be much more than the average dog owner spends on food per month.  

According to Statista, the average dog owner spends $442 per year on pet food or $37 per month.  

TextDescription automatically generated

Again, if you project that your average customer is going to spend $300 per month, you better have a good reason why your average monthly spend per customer is so far outside of the industry standards. 

  1. Average Customer Churn Rate for eCommerce

Finally, our last key assumption for eCommerce startup financial projections is to project a reasonable churn rate for your customers.  In other words, what percentage of your customers leave each month or year?  

According to Ominconvert, the average retention rate for ecommerce brands is just 30%.  In other words, 70% of your new customers will “churn” or not purchase again. 

Graphical user interface, text, applicationDescription automatically generated

You need to assume that most of your new customers will never buy again.  If your projections don’t include a reasonable church rate, your projections are likely too optimistic. 

How to know whether your ecommerce startup projections are reasonable

Once you have done your research and made reasonable assumptions based on research, you can determine whether your projections align with what other ecommerce startups have experienced.  We studied 234 tech startups and found actual revenue for ecommerce startups.  I encourage you to see how your projections line up to what other direct to consumer / ecommerce brands experienced.  You can see some of our revenue data below:

There you have it! The 5 essential financial assumptions you need to have in order to create reliable and accurate financial projections for an ecommerce business. If you'd like to use a template in order to put these assumptions to work quickly, check out our three ecommerce templates that guide you through making projections simply.

About the Author

Adam is the Co-founder of ProjectionHub which helps entrepreneurs create financial projections for potential investors, lenders and internal business planning. Since 2012, over 50,000 entrepreneurs from around the world have used ProjectionHub to help create financial projections.

Other Stories to Check out

How to Finance a Small Business Acquisition

In this article we are going to walk through how to finance a small business acquisition and answer some key questions related to financing options.

How to Acquire a Business in 11 Steps

Many people don't realize that acquiring a business can be a great way to become a business owner if they prefer not to start one from scratch. But the acquisition process can be a little intimidating so here is a guide helping you through it!

How to Buy a Business with No Money Down

Learn the rare scenarios enabling the purchase of a business with no money down and delve into the complexities of selling via seller notes, highlighting the balance of expanded opportunities and inherent risks in these unique financial transactions.

Have some questions?
Let us know and we'll be in touch.

Thank you! Your submission has been received!
Oops! Something went wrong while submitting the form.