Marketsizing question MECE

First of all, it's important to be very precise about the question being asked.

If the question is: "Should we enter this market, and if so, what revenues can we expect?" then this is fundamentally different from: "We have already decided to enter the market. What revenues can we expect?"

In the first case, you need to assess both the attractiveness of the opportunity and the expected revenues. In the second case, the entry decision has already been made, so the focus is mainly on estimating revenues and defining the go-to-market approach.

For the first type of case, I would typically expect a structure along the lines of:

1. Market attractiveness
   • Market size and growth
   • Customer needs
   • Competitive landscape
   • Industry dynamics
2. Expected revenues / economics
   • Market share assumptions
   • Pricing
   • Volume
   • Revenue potential
3. Go-to-market strategy
   • Capabilities required
   • Channel strategy
   • Product positioning
   • Key risks and mitigations

Regarding your specific question, I would not worry too much about whether buckets 1 and 2 are perfectly MECE. There is some natural overlap because market size is an input into revenue estimation. However, the structure is still logically sound and easy to communicate.

That said, if the case is purely about estimating revenues after the entry decision has already been taken, I could also see market size and market share being combined into a single "Revenue Potential" bucket.

The only thing I would probably change is the naming of the third bucket. Rather than "Capabilities & Risks," I would call it "Go-to-Market Strategy," which naturally includes capabilities and risks but also broader operational levers such as channels, pricing, partnerships, and product positioning.

Hope this helps.

Best,
Franco

I wouldn't worry too much about the MECE aspect here.

Strictly speaking, you're right that market size and market share are not fully independent, since estimated revenue is usually:

Market Size × Market Share

So from a purely logical perspective, they could sit under the same branch.

That said, in a real interview I would have no issue with the structure you proposed because it reflects a very natural decision-making process:

1. Is the market attractive enough? (market size)
2. How much of it can we realistically capture? (market share / revenue)
3. What do we need to succeed and what are the risks? (capabilities & risks)

In fact, I might even prefer your version because it mirrors how executives often think about market entry.

One thing I've noticed is that candidates sometimes become overly obsessed with perfect MECE. Interviewers generally care much more about whether your structure is:

• logical
• easy to follow
• relevant to the question

than whether every branch is mathematically independent.

So I would not merge buckets 1 and 2 just for the sake of "being more MECE." Your approach sounds perfectly reasonable to me.

Your structure works in practice but it's not strictly MECE. Market size and market share are sequential, not parallel. Both feed into revenue, so technically they should sit together under one bucket.

The cleaner MECE way is three parallel branches. First, revenue potential, and within that you calculate market size, then market share, then multiply. Second, capabilities needed to capture the revenue. Third, risks and considerations.

Your version isn't wrong though. Most candidates split market size and share for ease of explanation, and interviewers follow the logic without flagging it. It rarely costs you anything in real interviews.

The thing to remember is MECE matters most at the top of your tree. At the sub-branch level, what really matters is correct math and clean signposting as you walk through it.

A useful pressure-test, ask yourself "if I removed one branch, does the analysis still hold?" If yes, you're probably MECE. If no, you have overlap somewhere.

Good luck.

Your structure has no depth. As such it doesn't provide much insight on how you are going to solve this problem. If you hadn't broken down revenue between Market Size and Market share, you would only be repeating the question back to the interviewer.

So... sure, it is MECE: Revenue = Market Size * Market Share.

But as an approach, it is really weak.