TRM vs TAM: The Marketing Math Bootstrappers Need

Most bootstrapped founders don’t have a “market size” problem. They have a reach problem.

You can build a solid product, write decent content, even run a few ads… and still stall at $5k–$20k MRR because the uncomfortable truth is this: your growth is capped by how many ready-to-buy people you can realistically get in front of. Not by what a Gartner report says the industry is “worth.”

This is why Rob Walling’s idea from Startups for the Rest of Us—TRM (Total Reachable Market) instead of TAM (Total Addressable Market)—is one of the most practical marketing frames for founders building without VC.

This post is part of our SMB Content Marketing United States series, so everything below is written with a budget-conscious operator in mind: your “marketing team” might be you, a contractor, and a tool stack you can justify on revenue.

TRM beats TAM because it’s based on reality

TAM is a vanity number for VC decks. TRM is a planning number for bootstrappers.

TAM (Total Addressable Market) is top-down: someone estimates the entire category spend, then assumes you can capture a meaningful slice. That’s fine when you’re raising millions and can buy distribution.

TRM (Total Reachable Market) is bottom-up: how many people can you realistically reach with the channels you can actually execute? That difference matters when you’re running lean.

Here’s a snippet-worthy way to think about it:

If you can’t reach buyers at scale, your TAM doesn’t matter.

A simple TRM model you can use this week

A practical TRM estimate comes from three inputs:

1. Buyer flow (monthly): how many “ready-ish” buyers exist each month?
2. Channel capture: what percentage of that flow can you realistically win?
3. Revenue per customer: what’s your average monthly gross margin per account?

A basic equation:

TRM MRR Potential = (Monthly Ready Buyers) x (Realistic Capture Rate) x (Avg MRR)

Example (intentionally conservative):

• 800 people/month searching buyer-intent terms (“HIPAA secure form tool”, “SOC 2 vendor onboarding”, etc.)
• You can capture 3% from SEO + review sites + outreach combined (24 customers/month if you’re strong)
• Average plan is $149/month

That’s $3,576 new MRR per month on a good month.

If your plan requires $20k/month in new revenue to keep up with your burn, you’ve just learned something important—without needing a mythical TAM.

Where “monthly ready buyers” actually comes from

For bootstrapped SMB marketing, you don’t need perfect data. You need order-of-magnitude correctness.

Use:

• Search Console + keyword tools (for buyer-intent terms)
• Review site category traffic (G2/Capterra style channels, if relevant)
• Cold outreach list size (ICP count with contactability)
• Ecosystem marketplaces (Shopify, HubSpot, Slack, Jira, etc.)

The point of TRM isn’t accuracy. It’s sanity. It stops you from building a go-to-market plan that assumes 1,000 customers/month when the whole category might only have 300 active switchers.

A competitor acquisition is a marketing move, not just finance

Buying a competitor can be cheaper than “earning” the same customers through content marketing, ads, and sales—if you manage the transition well.

Rob’s caution is correct: acquisitions carry real load—legal, operational, technical, and emotional. If you buy a tiny competitor doing “a couple thousand a month,” you can easily spend more in time than the deal is worth.

But for bootstrapped founders who want growth without VC, acquisitions can be a smart alternative to paid acquisition.

When acquiring a competitor makes sense (bootstrapped edition)

A competitor acquisition tends to work when at least one of these is true:

• Customers have low switching costs (simple workflows, limited data migration)
• The competitor’s product is stagnating, but the customers are healthy accounts
• You can improve retention quickly (better support, stability, integrations)
• The deal structure includes a seller transition period

And here’s the biggest filter:

If you don’t have a clean plan to keep customers paying after the sale, you’re not buying revenue—you’re buying churn.

Two transition strategies that reduce churn

1) Migrate customers into your product (fast, but risky).

This works if your product is clearly better and switching is manageable.

Tactics that raise migration rates:

• White-glove onboarding for top accounts (top 10–20% by revenue)
• Import tools, or at least assisted CSV/API migration
• “Same price for 12 months” guarantee to remove fear
• A deadline with incentives (discount or feature access)

2) Run the acquired product as a “melting ice cube” (slow, but stable).

Rob described this approach: keep the old app running, shut off new signups, redirect marketing, and let the legacy revenue gradually decline. This often reduces chaos.

It’s not glamorous, but it’s extremely bootstrapped-friendly because it:

• Avoids a rushed migration that creates support tickets
• Buys you time to rebuild the best parts in your core product
• Lets customers self-select when (or if) they switch

Structuring the deal around migration outcomes

One of the smartest ideas from the episode: make part of the purchase price contingent on how many customers successfully transition.

If there’s a plausible migration range (say 30% to 80%), you don’t want to overpay assuming the high case.

Practical structures:

• Earnout based on retained MRR after 90/180 days
• Seller note paid monthly from actual collected revenue
• Holdback released when key accounts migrate

This turns an acquisition into a controlled customer acquisition program—without VC.

Finding a developer co-founder: the hard truth (and the workable path)

If you’re non-technical, trying to build SaaS without a technical co-founder is usually a grind. Not impossible. Just predictably painful.

Rob’s stance is sharp and I agree with it for most bootstrapped SaaS: a solo “business” founder + outsourced dev shop often hits a ceiling because nobody owns long-term technical quality the way an actual founder does.

Why “equity-only” offers rarely work

A good developer can bill $100–$200/hour (sometimes more). Asking them to work “for equity” means asking them to invest tens of thousands of dollars in unpaid labor into something that statistically won’t hit product-market fit.

Ideas aren’t worthless, but they’re not scarce.

What is scarce is a founder who can bring distribution.

What actually attracts strong technical partners

If you want a developer co-founder (or founding engineer), bring one of these to the table:

• Proven distribution: a niche email list, a YouTube channel, a community, partnerships
• Pre-sold demand: 5–10 LOIs, paid pilots, or committed design partners
• A clear go-to-market plan: specific channels, messaging, ICP, pricing logic
• Willingness to match effort: they build, you sell—week by week

A clean rule:

If you want someone to bet their nights and weekends, you need to bet yours too—on marketing and sales.

If you can’t find a co-founder, consider “paid + meaningful equity”

Bootstrapped doesn’t mean “no money.” It means you’re disciplined with it.

A sustainable approach is offering:

• A real (even if modest) salary
• 10–25% equity depending on seniority and commitment
• Clear ownership: codebase quality, architecture decisions, hiring roadmap

This is often cheaper than endless rework from under-scoped outsourcing.

Outsourcing without VC: when it works, and how to avoid regret

Outsourcing can work well for bootstrappers when you treat it as a productized capability—not a replacement for product leadership.

The sponsor example in the episode (DevSquad) highlights the useful version of outsourcing: you’re not hiring “random developers.” You’re hiring a team with product management, UX, QA, and DevOps.

That matters because many outsourced projects fail for one boring reason: the founder has to micromanage every decision.

A bootstrapped outsourcing checklist

If you’re using an agency/team to build your MVP or major features, do this:

• Define success in numbers: time-to-first-value, activation rate, core workflow completion
• Write user stories, not feature lists: “As a clinic admin, I need…”
• Ship weekly: small releases expose misunderstanding early
• Own the product decision-making: you decide priorities, not the dev team
• Budget for iteration: MVP rarely works on v1

Outsourcing is most effective when paired with strong marketing validation—because it prevents you from building expensive guesses.

TRM-first marketing plan for SMB founders (a practical template)

TRM becomes useful when you turn it into channel decisions. Here’s a simple way to do that.

Step 1: Pick 1–2 channels you can actually sustain

For SMB content marketing in the US, the most repeatable bootstrapped channels are:

• SEO content + programmatic landing pages (when the niche is clear)
• Review sites / directories (if your category shops there)
• Cold email to a tight ICP (especially for B2B)
• Ecosystem marketplaces (Slack/Jira/Shopify/HubSpot apps)

Step 2: Estimate reachable demand per channel

Build a quick spreadsheet:

• Buyer-intent search volume for 10–20 terms
• Directory impressions/clicks if available
• List size of your ICP in the US (e.g., 8,000 clinics of X type)
• Expected reply rates (1–5%), close rates (10–30%), ACV

Now you can sanity-check your goals.

Step 3: Set pricing that matches the cost of your constraints

Rob’s HIPAA point was blunt and correct: compliance implies higher pricing. Even if you can bootstrap HIPAA, it changes your market.

If your sales motion is heavier (compliance reviews, procurement, longer onboarding), a $49/month plan often won’t support it.

TRM thinking forces the pricing question early: if only 100 buyers/month exist, you need higher ACV or you’ll stay small forever.

The bootstrapped advantage: you can win with focus

Bootstrapped startups don’t win by “capturing the market.” They win by capturing a reachable slice of a specific niche and serving it better than anyone else. That’s why TRM is such a useful lens.

If you’re building without VC, here are the plays worth taking seriously:

• Replace TAM slides with TRM spreadsheets
• Treat acquisitions as a customer acquisition channel, not a trophy
• Don’t gamble on “equity-only” dev help—bring distribution or bring cash
• Use outsourcing to accelerate execution, but keep product leadership in-house

The next step is straightforward: pick one market, pick one channel, and measure reach like your runway depends on it—because it does.

What would change in your marketing plan this week if you stopped asking “How big is the market?” and started asking “How many buyers can I realistically reach in 90 days?”