Founders · 15 min read

The first hundred customers: which tools actually matter.

An honest stack for the first revenue cohort — what to use, what to skip, what costs less than it looks, and the order to buy them in.

Founders waste an embarrassing amount of money on tools before they have customers, and then waste more once customers arrive — usually on the wrong tools, in the wrong order, at the wrong tier. The right zero-to-100 stack is smaller than founders expect and biased toward "things you'll use every day", not "things that look good in a deck".

This is the stack I'd use if I were starting a B2B SaaS today, with the prices and the reasoning. Total monthly cost at 100 customers and €60K MRR: under €600. Most of which is Stripe fees.

What you actually need

The honest list of tools the first revenue cohort touches:

  1. A domain.
  2. A way for customers to find the marketing site.
  3. The marketing site.
  4. The product itself.
  5. A way to take payment.
  6. A way to send transactional email (signup, reset, receipt).
  7. A way for customers to ask you for help.
  8. A way to know what they're doing in the product.
  9. A way to know your finances aren't quietly broken.

That's it. Anything else — CRM, marketing automation, A/B testing platform, custom analytics warehouse, on-call rotation, a Notion HQ — is premature past customer 100. Most of them are still premature past customer 1,000.

The stack

Domain

Buy at Cloudflare or Porkbun. Avoid GoDaddy, avoid registrar lock-in, avoid the registrar that bundles "free" hosting. Cost: €10–€15/year. Pay for the privacy (free at both providers). Don't buy a six-letter domain hack — buy the obvious .com or your country's TLD even if it's expensive. The first hundred customers will type it, mistype it, and tell their colleagues to type it. Spell-it-once-and-you're-right is worth €100/year of premium.

How customers find you

For B2B SaaS in the first revenue cohort, the channels that actually deliver are:

Don't pay for SEO tools (Ahrefs, Semrush, Moz) yet. Use Google Search Console (free) and read the actual reports. Don't buy a CRM yet — a Google Sheet with one row per lead is faster, cheaper, and you'll outgrow it at customer 50 anyway.

Marketing site

Build it with Marcus in an afternoon. The site needs: hero with the offer, three benefits, social proof when you have it, pricing, FAQ, signup form. Total cost: €29/project/month on the Builder tier — one tenth what the same site costs to maintain on a hand-coded stack with a separate hosting provider, CMS, form handler, and SSL renewal.

Don't buy Webflow yet, don't buy Framer yet, don't buy a Wordpress hosting plan. The marketing site changes weekly in the first quarter; an AI builder is the right tool for that velocity.

The product

If your product is a B2B SaaS in the early phase, build it with Marcus too. Builder tier covers signup, auth, multi-tenant data, billing, admin console — about 60% of what a hand-built v1 takes. Cost: €29/project/month. As above, don't migrate to a hand-built stack until you cross €30K MRR or hit a real engineering bottleneck.

If your product is hardware, a marketplace, or something Marcus genuinely can't build (deep ML, real-time, regulated finance), this guide is the wrong reference. Read the marketplace and hardware-specific founder posts; this stack is for software-only B2B.

Payments

Stripe. Don't shop around. Stripe Checkout for the first 100 customers is fast, well-documented, and the fees (2.9%+€0.30 in the EU) are unremarkable. Don't build custom checkout. Don't use Paddle until you actually need a merchant of record (you don't yet).

Set up Stripe in an hour. Three modes you need: subscription (most common), one-time payment (occasional), and a saved-card-for-future-use mode for usage-based billing if relevant. Don't enable currencies you don't sell to yet — every extra currency is a settlement reconciliation chore.

For Russia, Belarus, and CIS — use YooKassa as a secondary provider. The integration adds two days. Worth it: the conversion uplift in those markets from local payment methods is 20–40%.

Transactional email

Resend, Postmark, or Sendgrid. Pick one in five minutes; they're equivalent for the first 100 customers. Set up DKIM, SPF, and DMARC properly — this is the single most-skipped step that bites you at customer 50, when half your password resets land in spam.

Cost: free up to 3,000 emails/month at Resend. €10–€15/month at slightly higher volume. Don't pay for Mailchimp; you don't have a marketing-email use case yet (newsletters are not the first 100 customers' job to be done).

Customer support

For the first 100 customers, support is your founder's inbox. support@yourdomain.com with a 24-hour response SLA written on the contact page, answered by a human, with a CC to one teammate so vacation doesn't break it.

Don't buy Intercom, Zendesk, or Crisp. They cost more than the support volume justifies, and they introduce a layer of "support tooling" between you and your customers that you should not want at this stage. The closest you should come to a help-desk tool is a shared inbox in Gmail or a Help Scout free tier.

The single thing worth buying at customer 50 is a public status page if you have any availability variance. Better Stack and Statuspage start at $30/month. Don't bother before that.

Product analytics

The honest answer: you don't need a real analytics tool for the first 50 customers. Read the Stripe dashboard for revenue, the Marcus-built admin console for usage, and have your customers on a phone call for "why aren't they using feature X". You'll learn more than any analytics tool would tell you.

Around customer 50, install PostHog (free up to 1M events/month, EU-hosted option) or Amplitude (free up to 10M events/month). Track three events: signup completed, first key action, returning visit. That's it. Don't track "button clicked"; you'll drown.

Financial visibility

The simplest stack: a monthly P&L spreadsheet, populated by hand in 30 minutes from Stripe's monthly export and your bank account. No QuickBooks yet. No Xero yet. No CFO-as-a-service yet.

If you're an EU company, get a real accountant (€100–€200/month for basic compliance). They'll handle VAT registration, quarterly filings, and the annual report. Don't try to DIY this; the time cost and risk are higher than the bill.

What to skip

Founders waste budget on these tools before customer 100, every time:

The total monthly bill

For a typical B2B SaaS at 100 customers with €60K MRR:

Total non-Stripe spend: ~€600/month. Including Stripe fees: ~€2,600/month. That's 4–5% of revenue, which is well within the 5–8% range mature SaaS spends on tooling.

If your tool spend is significantly higher than that — €3,000+/month at 100 customers — you've over-bought. Audit, cancel three things, and put the money toward customer acquisition or a part-time hire.

The order matters

The order to buy the stack in:

  1. Domain (week 0).
  2. Marketing site (week 0).
  3. Product (week 1).
  4. Stripe (week 2, when you have first lead willing to pay).
  5. Email (week 2, before launch).
  6. Accountant (week 3, before first invoice).
  7. Paid acquisition (week 4, after the launch wave subsides).
  8. Analytics (around customer 30).
  9. Status page (around customer 50).

Resist anything else until customer 100. The tools you wish you had are usually the tools that solve a problem you don't have yet.