Behind-The-Scene: From one comment to a tiny funnel

Somebody left me this comment on my last tool:

“This is a great tool, is it possible to also include lifetime subscriptions, monthly visitors, bounce rate if possible… other than that it’s really a solid tool.”

At first, my brain was like: yes, add all the knobs!
Lifetime toggle! Bounce slider! Visitor types dropdown!
And then I realized… I was about to build a spreadsheets-from-hell simulator instead of something people actually touch.

The “aha” moment

I scribbled the funnel on a sticky note:

Traffic → Signups → Paid → New MRR → Steady-State

That’s it. Five boxes. Five dials. If you can’t explain your model in one napkin sketch, you’re doomed.

So I asked: Do lifetime subs really need their own input? Nope, that’s just ARPU smoothed over 12 months.
Do I need bounce rate? Nah, signup rate already tattles on your bounce.
Monthly visitors? That’s just daily traffic × 30. Extra button = extra confusion.

Rule of thumb I kept repeating: if two inputs always multiply together, kill one.

Defaults > paralysis

Most people don’t even know their signup or pay rates, so I baked in “don’t-embarrass-yourself” defaults:

• Signup rate: ~8% (slider range 5–10%)

• Pay rate: ~12% (slider range 5–20%)

• Net churn: 4% (because churn is the silent killer)

• ARPU: pick a round dollar, done

And if you do know your signups/day, flip a toggle and skip the signup slider. Simple enough that you don’t need to ask in the comments.

The fun parts

• Step Path UI: big boxes, big numbers, arrows → it literally looks like the funnel we all draw on napkins.

• Target helper: type your dream MRR, it tells you how much traffic you actually need. (Prepare to cry.)

• Bottleneck detector: highlights if your signup or pay rate is the weakest link.

• Presets: Lean / Average / Aggressive. (Basically “me right now” vs. “me in my pitch deck.”)

Math under the hood is laughably tiny:
\nnewMRR = (traffic × 30 × signupRate × payRate) × ARPU\nsteady = newMRR / churn\n\nThat’s literally the whole thing.

Shipping it

I nearly added an “advanced metrics” panel (cohort charts, lifetime toggles, blah blah) but forced myself to hit publish first.

Reactions?

• “Now I actually see where I’m leaking.”

• “Didn’t know my rates, used defaults, still useful.”

• “The traffic needed for $10k MRR hurt my feelings but thanks.”

Which is exactly the vibe I was going for. Brutal honesty, minimal pain.

Takeaways

• More knobs ≠ more clarity.

• One bottleneck is better than 20 dashboards.

• Ship the napkin version first.

The comment that could drag me into feature creep actually gave me the best constraint: keep it tiny, keep it shippable.

Check it out here: Traffic-to-MRR Path