01
A viral product does not have a free plan
Free users raise support and server costs, and under 3% ever convert.
The playbook
32 principles of a viral product
Indie hacker Marc Lou distilled five years of building 35 startups in public into 32 rules for making a product spread on its own. Here is the full list, plus a free tool that grades your site against every one of them.
Free tool
How viral is your site?
Paste your URL. We scan your homepage, grade it against all 32 principles, and rewrite your copy the Marc Lou way. Free, no signup.
02
A viral product has three colors
Black text, white background, one color for the buy button. Every extra color dilutes what matters.
03
A viral product uses numbers instead of adjectives
“Fast” is forgettable. “Save 4 hours every week” is not.
04
A viral product ends with a footer people want to share
97% of visitors will not buy, but they might share. People remember what they see last.
05
A viral product treats the OG image as a YouTube thumbnail
The link preview gets seen more than the website itself. Design it like a thumbnail.
06
A viral product reveals one idea per screen
One screen, one message, just like a feed.
07
A viral product has a headline a fifth grader can understand
Complexity kills curiosity. Your mum should get it.
08
A viral product has a hard paywall
Signups do not pay the bills. Ask for payment before asking for data.
09
A viral product has copy only you could write
If a competitor could paste your landing page onto theirs, it is too generic.
10
A viral product shows the product before it explains it
A demo communicates more than paragraphs of text. Show, do not tell.
11
A viral product does one thing
Nobody remembers Swiss Army knives. Be known for the tool that solved the problem.
12
A viral product uses popcorn pricing
Three choices, no spreadsheet: good, better, best.
13
A viral product rides a wave
Build around what people already discuss. The wave does half the marketing.
14
A viral product steals its best copy from customers
Customers already describe the product better than you do. Write like they talk.
15
A viral product has a founder people can see and hear
People buy from people. A founder screen recording beats a corporate promo.
16
A viral product makes pricing impossible to miss
Visitors read pricing to understand the product, not just the price. Put it in the header.
17
A viral product has a headline people remember the next day
Write five, show friends, wait 24 hours, keep the one that sticks.
18
A viral product has an emotional headline
People remember feelings, not features. Make them laugh, say wow, or lean in.
19
A viral product does something people have never seen before
Nobody shares another clone. Surprise people.
20
A viral product can be sold from the hero section alone
80% of visitors never scroll past the hero. Win them in seconds or not at all.
21
A viral product shows empathy before it sells
Describe the problem better than the visitor can, and they will trust the solution.
22
A viral product has one call to action
Multiple paths means many choose none. Give people one next step.
23
A viral product has a name people remember
Use words people already know. No wordplay that needs explaining.
24
A viral product sells a human desire, not a feature
More money, more time, better health, more status, less pain. Features are just the vehicle.
25
A viral product lets people try the product before buying it
Put the best features on the landing page. Let people play before they pay.
26
A viral product does not use weak words
“Most” and “many” mean nothing. Make claims people can picture and challenge.
27
A viral product does not have a subscription
One-time payments are 10x easier to sell. Only charge monthly if you cannot ship without it.
28
A viral product has a call to action that says what happens next
“Analyze my website” beats “Get started”. Remove uncertainty.
29
A viral product does not launch without testimonials
A page without proof asks strangers for blind trust. Collect it before traffic.
30
A viral product can be described in under 10 words
If you cannot explain it in one sentence, your users will not either.
31
A viral product compares itself to competitors
People care why they should switch. A simple comparison table makes the decision obvious.
32
A viral product is more expensive than its competitors
Nobody talks about the second cheapest option. Charge more.
Summarized from 32 Principles of a Viral Product by Marc Lou. Read the original on X for the full write-up behind each one.
Leaderboard
The most viral sites
Best score per domain, top 10. Fix your site and re-scan to climb.
Knowing the rules is optional.
Running them daily is not.
Viraloop turns viral principles into a system: on-brand posts, generated and published to every platform, every day.