Unlocking the Market Opportunity Slide in Your Pitch Deck

Brett Brohl
Bread and Butter Ventures
5 min readNov 7, 2023


**Watch Brett’s Guide to a Seed Stage Pitch Deck for an overview of all slides in your deck**

In the world of startup pitch decks, the market opportunity slide (where you usually see TAM, SAM, SOM) is another one of those pitch deck slides that founders often glaze over, end up worrying about too much and then in the end not putting much time into. When done well it is a valuable process for founders to go through and provides real insight to an investor. This slide is your opportunity to demonstrate not only the size of the market you’re targeting but also how you plan to navigate and conquer it.

We’re continuing our series that deep dives into the individual slides that are part of a seed stage pitch deck. In today’s post I’m going to dissect the market opportunity slide and give you some tips to make sure this slide isn’t a waste of everyone’s time.

Deciphering TAM, SAM, and SOM: What Are They?

TAM, SAM, and SOM — you’ve heard these acronyms and you know you need them in your deck but what do they mean and how do they contribute to your pitch?

TAM (Total Addressable Market): Think big. Your TAM is the grand vision — the entire landscape of spending related to the problem your product (and even future products) or service addresses. For instance, if you’re a U.S. based food safety software company tackling pathogens, allergens, and foreign objects in food manufacturing, your TAM covers the total spending on food safety across the entire food value chain. This number is your upper limit, your ultimate potential, if you were to capture the entire market.

SAM (Serviceable Addressable Market): Get specific. Your SAM is a more refined segment of your TAM. It focuses on a demographic, geography, or more specific target market that aligns with your current product’s capabilities. Continuing with the food safety software example, your SAM would encompass the subset of spending on food safety within specific parameters — perhaps the spending within food manufacturing facilities based in the U.S. that are utilizing or interested in utilizing software solutions.

SOM (Serviceable Obtainable Market): Who are you selling to now? Your SOM represents the slice of your SAM that you realistically aim to capture in the short term. It’s a tangible checkpoint on your journey. Sticking to the food safety software scenario, if your initial focus is on allergen detection within enterprise food manufacturing, then your SOM comprises large enterprises in the U.S. within that sector already spending money on or actively seeking allergen detection solutions.

Why Do TAM, SAM, and SOM Matter?

At its core, the market opportunity slide is a window into your strategic thinking, a mirror reflecting how well you comprehend your business landscape. While numbers matter, it’s the insight behind those numbers that truly counts.

TAM: How are you a huge company? Your TAM reveals your grand vision — it shows how expansive you perceive your business’s potential. This number demonstrates the ultimate scale you’re aiming for, providing investors a glimpse into your aspirations.

SAM: The SAM delves deeper into your target audience, your current product’s potential and demonstrates your understanding of the nuances within the market. It’s a reflection of your ability to identify the right segment for your current product or service and your potential to capture a substantial portion of that segment.

SOM: The SOM is the embodiment of your go-to-market strategy. It showcases your immediate focus and the milestones you aim to achieve. Investors look at your SOM to understand how effectively you’ve planned your initial steps in capturing a slice of the market.

Two Approaches to Define Market Sizes: Top Down and Bottoms Up

When it comes to determining market sizes for your TAM, SAM, and SOM, there are two distinct methodologies — top down and bottoms up. Each approach provides valuable insights into your strategic thinking and the context of your business landscape.

Top Down: This approach is suitable for more established markets where products or services similar to yours are already being sold or used. For instance, if you’re entering the CRM market, you can find existing data on global CRM spend. You can argue it is a fairly mature market with great data available, forming the basis for your TAM calculation. In fact, if you claim the market is significantly larger than current spend in a mature market you will have a lot of explaining to do!

Bottoms Up: When your venture targets a less established market, often referred to as a “blue ocean,” the bottoms-up approach is more appropriate. This approach involves breaking down your market opportunity by considering the specifics of your product, its price, and the potential number of customers. It is actually a really basic equation:

Potential Customers X Price

The nuance is in how you arrive at your number on either side of this algorithm. By calculating what you can sell your product for and identifying the number of potential customers, you can arrive at a more tailored market size estimation. For a bottoms up calculation be ready to defend the assumptions driving both sides of this simple equation.

If you are in a relatively new market that is smaller, don’t be afraid to throw a substantiated total market growth rate on this slide!

Both have challenges, but these two methods reveal how you’re conceptualizing and positioning your startup in the broader market context.

Navigating Pitfalls and Red Flags

A few common pitfalls that can undermine your credibility and clarity:

Incorrect Market: Avoid presenting the total market size of a vertical as your market. In other words, wour market size should reflect the relevant portion of the market that your product or service addresses. Back to our food safety example. In this situation an entrepreneur may incorrectly claim that their TAM is the total value of the food manufacturing industry. This is incorrect and kills your credibility. Your TAM is the total spend on food safety within the food manufacturing industry, unless one day you plan on being a food manufacturer! Don’t shoot yourself in the foot, be precise and provide transparent calculations. Too often software companies make this egregious error, focus on the potential for your software, not the industry itself!

Unsubstantiated Numbers: Whether you get your figures from a study, analysis, or your own calculations, always provide a reference or context for your market sizing. Cite reputable sources to validate your numbers and lend credibility to your claims.

Lack of Focus: While having all three metrics (TAM, SAM, SOM) can offer a comprehensive view, I’m okay with just focusing on TAM and either SAM or SOM. The goal is to showcase your big vision, your initial market approach, and your short-term objectives.

Final Thoughts

The market opportunity slide is more than just numbers — it’s a reflection of your strategic thinking and business acumen. Demonstrating a clear understanding of your business landscape, combined with well-defined TAM, SAM, and SOM figures, can leave a lasting impression on investors (and more importantly avoid a negative one!). Remember, it’s not just about presenting the market’s potential; it’s about revealing your thought process, strategy, and adaptability in reaching that potential.



Brett Brohl
Bread and Butter Ventures

Founder. Investor. Lobster Diver. General Partner at Bread &Butter Ventures. MD of Techstars Farm to Fork Accelerator in partnership with Cargill and Ecolab.