Engineering as Marketing: Free Tools That Grow a SaaS
Engineering as marketing means building a small free tool, like a calculator, grader or generator, that solves a job next to your paid product and sends the right people to it. HubSpot's Website Grader graded over 2 million URLs. Ahrefs, Shopify, Plausible and Castos all run free tool hubs today. For a bootstrapped SaaS, one weekend-sized tool can keep pulling search traffic and links long after a launch post is forgotten.
Key takeaways
- Engineering as marketing is one of the 19 traction channels in Gabriel Weinberg and Justin Mares's book Traction; Weinberg described it as building free tools that are complementary to your product.
- HubSpot's Website Grader launched in February 2007 and, by HubSpot's own count, went on to grade over 2 million website URLs.
- Ahrefs, Shopify, Plausible and Castos all run free tool hubs today; Plausible's says no account is required and everything runs in the browser.
- Pick a tool that does the task just before or just after your paid product, check search demand first, and keep version one client-side, login-free and small enough to ship in a weekend.
- Treat the tool as a product: give it its own landing page, an embed code for backlinks, one clear CTA, tracked events, and a budget for keeping its data current.
On this page 20
- TL;DR
- What engineering as marketing actually means
- Real examples, from the companies' own pages
- Step 1: pick the right tool idea
- Step 2: keep the build small (our rules)
- Step 3: give it a landing page that can rank
- Step 4: add an embed for backlinks
- Step 5: design the CTA
- Step 6: measure it
- Budget for maintenance
- 10 free tool ideas by SaaS category (ours)
- Common mistakes
- Frequently asked questions
- What is engineering as marketing?
- Is a free tool better than writing blog posts?
- How long should it take to build a free marketing tool?
- Should a free tool require an email address?
- How is this different from programmatic SEO?
- Launch your tool, then your product
- Sources
Short answer: Engineering as marketing means building a small free tool, like a calculator, grader, checker or generator, that does a job next to your paid product and attracts the people who would buy it. For a bootstrapped SaaS it is one of the few channels where a weekend of engineering can keep bringing in search traffic, links and signups for years without an ad budget.
Every fact and quote below comes from a page we fetched on 9 Nov 2026 and is linked inline. The build rules, tool ideas and mistakes list are ours and are marked as such.
TL;DR#
- The term comes from Traction. Gabriel Weinberg and Justin Mares list engineering as marketing as one of 19 traction channels. On a 2014 podcast Weinberg said it means "building essentially free tools that are complementary to your product" (Startups for the Rest of Us, ep. 199).
- The classic example is HubSpot's Website Grader, launched in February 2007, which HubSpot says went on to grade over 2 million website URLs (HubSpot).
- It is still standard practice. Ahrefs, Shopify, Plausible and Castos all run free tool hubs today.
- Pick the upstream or downstream task of your paid product, check search demand, and ship a client-side, login-free version one in a weekend (our rule).
- Treat the tool like a product: its own landing page, an embed code, one CTA, tracked events and a maintenance budget.
Disclosure: ZeroRaised publishes this guide and is a launch site for bootstrapped products. We run our own free tools, which we mention below as a labelled example. We have no commercial relationship with any other company named here.
What engineering as marketing actually means#
Traction sorts the ways a startup can find customers into 19 channels; engineering as marketing is number 10 in the episode's show notes. Weinberg said on that episode that "there wasn't even a good name for it, which we termed engineering as marketing", and that "HubSpot has done a great job of this with their marketing grader website". He also named "SEOmoz" and its "followerwonk tool" as another example (Startups for the Rest of Us, ep. 199).
The key word is complementary. A free tool is not a free tier of your product. It is a separate, smaller thing that solves a nearby problem for the same audience, and then points them at the bigger solution.
Our read on why it suits bootstrapped founders: you already have the scarce skill, the output is an asset rather than a recurring spend, and useful tools attract links more naturally than a sales page. It pairs well with the channels in our guide to free marketing channels for bootstrapped makers.
Real examples, from the companies' own pages#
| Company | Free tool(s) | What the company's own page says | Link to the paid product |
|---|---|---|---|
| HubSpot | Website Grader | "HubSpot's original free marketing tool", launched February 2007, "grading over 2 million website URLs" | Inbound marketing software |
| Ahrefs | 18 tools listed, from a Backlink Checker to a Keyword Difficulty Checker | "While limited compared to a paid Ahrefs account, they're still immensely valuable for anyone who's just starting out in SEO." | Paid plans from $29/mo (Starter) |
| Shopify | 20 tools, including a logo maker, business name generator and profit margin calculator | "Free tools to grow your business" | "Start for free" signup CTA on the hub |
| Plausible | Conversion rate, ad cost and cookie banner traffic loss calculators, UTM builder and checker | "No account required. Everything runs in your browser." | Privacy-friendly web analytics |
| Castos | Dynamo art maker, RSS feed validator, podcast name generator and more | Dynamo is "Free, with no account." | Podcast hosting |
Sources: HubSpot, Ahrefs free SEO tools, Shopify tools, Plausible tools, Castos tools.
Website Grader started small: Dharmesh Shah wrote on Product Hunt that "I personally developed the original version of Website Grader" (Product Hunt). It grew steadily, not overnight: 250,000 unique URLs in its first year (HubSpot), 1 million by June 2009, and 2 million seven months later (HubSpot).
Plausible's cookie banner traffic loss calculator measures the exact problem its paid product removes, a neat fit with its pitch.
Our own example (labelled, it is us): ZeroRaised runs a payment fee calculator showing what Stripe, PayPal, Lemon Squeezy, Paddle and Polar take from a sale, with UK, EU and US rates. It needs no login, offers a free embed code, and its CTA points makers to launch on ZeroRaised. Its sibling on our tools page is a ramen profitability calculator.
Step 1: pick the right tool idea#
Our rule: the best tool does the task just before or just after the job your paid product does, for the same person.
- Upstream: the thing someone does before they need you. Shopify's business name generator and logo maker serve people who have not started a store yet.
- Downstream: the check someone runs after using a product like yours. Castos's RSS feed validator helps podcasters "check a feed for errors before you submit it to directories" (Castos tools).
- Diagnostic: a grader that scores the problem your product fixes. Website Grader is the pattern.
Then check that people search for it. Free options we verified today:
- Google Keyword Planner is "a free resource to help advertisers build keyword lists", but note that "Anyone with a Google Ads account can access the Keyword Planner tool after they create a campaign" (Google).
- Ahrefs' Free Keyword Generator and Keyword Difficulty Checker are on its free tools page (Ahrefs).
- Google Search Console helps you "measure your site's Search traffic and performance" (Search Console); look for tool-shaped queries you already show up for.
Our read on a passing idea: the query has tool-shaped intent ("calculator", "generator", "checker", "template"), the current results are clunky or ad-heavy, and the searcher could plausibly be your customer within six months. For a fuller keyword process, see our guide to SEO for bootstrapped startups.
Step 2: keep the build small (our rules)#
- Ship version one in a weekend. If it cannot be built in two days, cut scope.
- Client-side by default. No server means nothing to scale or break when a link goes viral.
- No login for the core result. Plausible and Castos both make "no account" a selling point.
- No paid APIs in the critical path. Otherwise you pay for strangers to use it.
- One input screen, one result, with defaults filled in so the first visit shows an answer.
- Shareable state. Put inputs in the URL so a result can be linked.
If an idea fails these rules, it might be a good product, just not a marketing tool.
Step 3: give it a landing page that can rank#
The tool page is also an SEO page. Our checklist:
- A title and H1 that match the search ("Podcast name generator", not "Introducing NameWizard").
- The tool above the fold, then a few hundred words explaining the method and data sources, with a "last checked" date if numbers change. Visible sources make it easier to trust and to cite.
- A short FAQ for the questions people ask after getting a result.
- Links from related blog posts, and a link from the tool to your best guide.
If one tool suggests hundreds of variant pages (one per currency, city or integration), that is a programmatic SEO project with its own risks; our programmatic SEO guide covers templates and Google's scaled content policy.
Step 4: add an embed for backlinks#
An embed turns other sites into distribution. Offer a copy-paste snippet (an iframe or a script tag) with a small "Powered by" link back to the tool page. Our own fee calculator offers one with the line "You can put the payment fee calculator on your own site or blog for free" (ZeroRaised).
Our rules: make the widget work at narrow widths, keep the credit link plain, and hide no extra links in it. Then tell bloggers, wiki maintainers, newsletter writers and course creators in your niche.
Step 5: design the CTA#
Earn the visit first, ask second. Our read:
- Put the CTA next to the result, not in a popup before it. Interest peaks right after the answer.
- Make the CTA about the next job. For example, a grader offers to fix the issues it found; a fee calculator points to launching the product. Ahrefs does this plainly, describing its free tools as "limited compared to a paid Ahrefs account" (Ahrefs).
- Offer an optional email capture for a saved report or a reminder, never as a gate on the core result.
- One primary CTA. Three competing buttons is how you get zero clicks.
Step 6: measure it#
Track three numbers per tool, at minimum (our setup):
| Metric | How to track it |
|---|---|
| Tool uses | A custom event when a result is shown, not just a pageview |
| CTA clicks | An event on the CTA, with the tool name as a property |
| Signups attributed to the tool | UTM parameters on the CTA link (for example utm_source=tool&utm_campaign=fee-calculator) carried into your signup form |
Plausible's free UTM builder can generate the tagged links.
Worked example (illustrative numbers, not real data): a tool page gets 3,000 uses a month, 4% click the CTA (120 clicks) and 10% of those sign up (12 signups). If 1 in 4 signups converts at $20/mo, that is 3 customers and $60 of new MRR a month. Measure your own rates before building tool number two.
Budget for maintenance#
Free tools are not free to own. Our read on the real costs:
- Data goes stale. A fee calculator is wrong the day a vendor changes its rates. Ours states when its figures were last checked and that they are rechecked monthly (ZeroRaised).
- Dependencies break. Client-side tools with no backend age best.
- Support questions arrive. Answer the common ones in the page FAQ.
If you cannot commit an hour a month per tool, build fewer tools.
10 free tool ideas by SaaS category (ours)#
Our suggestions, untested:
| SaaS category | Free tool idea | Why it fits |
|---|---|---|
| Invoicing | Late payment fee calculator | Upstream of chasing unpaid invoices |
| Email marketing | Subject line length and preview checker | Run before every send |
| Scheduling | Time zone meeting planner | The task before booking a call |
| Analytics | Sample size or A/B test significance calculator | Downstream of collecting data |
| Uptime monitoring | SSL certificate expiry checker | Diagnostic for the problem you monitor |
| HR or payroll | Contractor vs employee cost calculator | Upstream of hiring |
| Podcast or video | Episode length to word count estimator | Planning step before recording |
| Developer API | Cron expression explainer | Developers search it repeatedly |
| E-commerce | Shipping box dimensional weight calculator | Done before every shipment |
| Pricing or billing | Annual vs monthly discount calculator | Upstream of setting your plans |
Common mistakes#
Our read:
- Wrong audience. A viral meme generator brings traffic that will never buy accounting software.
- Gating the result behind an email form. It cuts usage and links.
- Over-building. Accounts and dashboards turn a weekend tool into a second product.
- Launching once and leaving it. Promote it like any launch: communities, newsletters, directories, outreach.
- No tracking. Without events and UTMs you cannot tell whether it sells anything.
- Letting data rot. A wrong calculator damages trust in the paid product too.
Frequently asked questions#
What is engineering as marketing?#
It is building a free tool, such as a calculator, grader, generator or checker, that attracts the kind of people who would buy your paid product. The term comes from the book Traction by Gabriel Weinberg and Justin Mares, where it is one of 19 traction channels. Weinberg described it as building free tools that are complementary to your product.
Is a free tool better than writing blog posts?#
Not better, different. Our read: a blog post answers a question once, while a tool does a job the visitor would otherwise do by hand, so it earns repeat visits, bookmarks and links. The two work well together: a guide that explains a topic can embed or link the tool that does the calculation.
How long should it take to build a free marketing tool?#
Our rule for a solo founder is that version one should ship in a weekend. That usually means a single page, all logic in the browser, no login and no database. If the idea needs accounts, background jobs or paid APIs to work at all, it is a second product, not a marketing tool.
Should a free tool require an email address?#
Our read: not to get the core result. Gating the answer behind a signup form cuts usage and makes people less likely to link to it. Offer an optional extra instead, such as emailing a saved report or a PDF, and put a clear CTA to your paid product next to the result.
How is this different from programmatic SEO?#
Programmatic SEO generates many pages from a template and a dataset to capture lots of long-tail searches. Engineering as marketing usually means one interactive tool on one strong page that people use, bookmark and link to. They can combine: a tool can power templated pages later, which our programmatic SEO guide covers.
Launch your tool, then your product#
A new free tool deserves a launch of its own. ZeroRaised is a launch site for products built without institutional VC: submit your product or tool for free. For more guides on growing without investors, join the ZeroRaised newsletter.
Sources#
- Startups for the Rest of Us, episode 199: Traction, with Gabriel Weinberg, last checked 9 Nov 2026
- HubSpot: Website Grader Analyzes Over 2 Million Sites, last checked 9 Nov 2026
- HubSpot: 250,000 Companies Test their Internet Marketing Acumen with Website Grader, last checked 9 Nov 2026
- Product Hunt: Website Grader discussion with Dharmesh Shah, last checked 9 Nov 2026
- Ahrefs free SEO tools, last checked 9 Nov 2026
- Shopify free tools, last checked 9 Nov 2026
- Plausible free tools and calculators, last checked 9 Nov 2026
- Castos free podcast tools, last checked 9 Nov 2026
- Google Keyword Planner, last checked 9 Nov 2026
- Google Search Console, last checked 9 Nov 2026
- ZeroRaised payment fee calculator, last checked 9 Nov 2026
- ZeroRaised tools, last checked 9 Nov 2026
Frequently asked questions
What is engineering as marketing?
It is building a free tool, such as a calculator, grader, generator or checker, that attracts the kind of people who would buy your paid product. The term comes from the book Traction by Gabriel Weinberg and Justin Mares, where it is one of 19 traction channels. Weinberg described it as building free tools that are complementary to your product.
Is a free tool better than writing blog posts?
Not better, different. Our read: a blog post answers a question once, while a tool does a job the visitor would otherwise do by hand, so it earns repeat visits, bookmarks and links. The two work well together: a guide that explains a topic can embed or link the tool that does the calculation.
How long should it take to build a free marketing tool?
Our rule for a solo founder is that version one should ship in a weekend. That usually means a single page, all logic in the browser, no login and no database. If the idea needs accounts, background jobs or paid APIs to work at all, it is a second product, not a marketing tool.
Should a free tool require an email address?
Our read: not to get the core result. Gating the answer behind a signup form cuts usage and makes people less likely to link to it. Offer an optional extra instead, such as emailing a saved report or a PDF, and put a clear CTA to your paid product next to the result.
How is this different from programmatic SEO?
Programmatic SEO generates many pages from a template and a dataset to capture lots of long-tail searches. Engineering as marketing usually means one interactive tool on one strong page that people use, bookmark and link to. They can combine: a tool can power templated pages later, which our programmatic SEO guide covers.