Founder Playbook · Sub Club by RevenueCat
11 tactics from Tanuj Chatterjee
How the World's #1 VPN App Reached 1 Billion Downloads
Watch the full episode“We started looking at our competitor's reviews right away to see what's missing in our app... what are people complaining about. And we started fixing those things. We started removing friction.”
Mine Your Competitors' Reviews to Find Product Gaps That Will Take You to #1
Super Unlimited's path to the #1 VPN spot on the App Store started with systematic review mining — not just their own, but competitors' too. Tanuj's engineering background made him read reviews as a product bug list: every complaint was a gap to close. This bottom-up method replaced expensive market research and delivered direct insight into exactly what would move the needle on ratings and downloads.
“We basically ask for ratings after we've delivered value to the user. That multiplied by the number of downloads... helps overall. We don't try to do too much gymnastics with trying to get more ratings.”
Ask for Ratings Only After You've Delivered Value — Organic Velocity Beats Artificial Prompts
Super Unlimited has 2 million+ high-quality ratings while explicitly avoiding rating-prompt tricks. Tanuj's rule: trigger the request only after the user has received real value from the session. At million-downloads-per-day scale, even a modest honest rating rate produces massive ASO velocity. Over-prompting or ill-timed requests kills both UX and rating quality.
“Our free-to-paid conversion is quite low and I'm okay with it because we have focused on the top of the funnel a lot... our free version is that good. The main goal is come and use the product.”
A Generous Free Tier Is the Top-of-Funnel Superpower — Don't Throttle It
Super Unlimited intentionally leaves money on the table by keeping its free tier genuinely unlimited. Tanuj sees low conversion not as a failure but as proof the free product is excellent. The denominator game — massive organic installs driven by a truly useful free experience — creates the scale that makes even small conversion rates into large absolute revenue. Throttling free users to force upgrades would destroy the very flywheel that powers growth.
“This head of support reports to our head of product. I want a mirror in front of the product team right there. Growth comes from product decisions and not just from marketing campaigns.”
Put Support Inside the Product Team for a Faster Feedback Loop
Super Unlimited routes customer support directly into the product org — not a monthly KPI review but a live signal feed. Service quality tickets from Uganda surface immediately in the sprint backlog. Tanuj frames it simply: support is the fastest feedback loop a product team can have, and adding organizational distance between them slows the company down by months per iteration cycle.
“Turkey banned Instagram for 11 days and we got 15 million downloads in 4 days... Once the spike is gone you hit a new normal at a higher level.”
Geopolitical Spikes Reset Your New Normal — Each Crisis Establishes a Higher Floor
Super Unlimited experienced multiple geopolitical surges — country-level social media bans, civil conflicts — that delivered tens of millions of downloads in days. The key insight Tanuj shares: after each spike recedes, the retention floor is higher than before. New users acquired in a crisis frequently stay. The strategy is to be ready (excellent product, low friction) so that when an external event drives a surge, it converts into a durable cohort, not just a vanity moment.
“We won't make any compromises on service quality. Those cost optimizations we do not touch. We won't touch it ever.”
Never Compromise on Service Quality to Cut Costs — It Destroys the Trust That Drives Growth
Tanuj draws a hard line: infrastructure cost cuts that degrade service quality are off the table permanently. Super Unlimited serves users in loss-making markets (Myanmar, some emerging economies) by choice because the company's growth engine runs on trust. Even when ad monetization doesn't cover server costs in certain countries, the global rating and referral reputation is worth more than the marginal savings. The lesson extends to AI apps today: open-source model swaps that reduce response quality destroy the product value that earned users in the first place.
“Do we have this algorithm... for these five countries? Let's just launch it. For the rest we can build over time. We could be wrong — in which case we iterate and get it right.”
Ship Features in Small Country-Scoped Batches via Feature Flags Before Global Rollout
When Super Unlimited rebuilt its server-selection algorithm, they resisted the urge to launch globally at once. Instead they used feature flags to ship to five countries first, accepted the risk of being wrong, and iterated before expanding. Tanuj calls this 'doing it in smaller chunks rather than building a big massive Taj Mahal and launching it' — a philosophy that applies to any complex feature where a bad rollout would affect tens of millions of users simultaneously.
“The first 85% is very easy. But after that every 1% is hard work. Sometimes differentiating great products from commodities is — do they just always work?”
The Last 10% Is the Entire Product — Edge Cases Define Who Wins in Commoditized Categories
VPN is a commodity in the first 85% — open source stacks exist, the core tunnel functionality is a known problem. Super Unlimited won the category by obsessing over the edge cases: reconnecting after a dropped cell tower transition, serving a user whose hotel blocks their IP, handling 3G in Nepal. Their QA engineer walked elevator shafts with debug builds to simulate real-world disconnects. In any category where competitors stop at 85%, the 15% of edge cases is the actual moat.
“We are mobile first and we have an advantage because desktop people pay more — but there's a trade-off. It's scale, loyalty, LTV.”
Build for Mobile First, Win on Scale — Desktop Competitors Have Higher ARPU but Lower Reach
Super Unlimited chose to own mobile first when desktop VPN players had higher-paying subscribers. Tanuj acknowledges the trade-off honestly: desktop users have higher ARPU and lower churn, while mobile delivers massive scale with lower individual LTV. His bet paid off: a billion downloads on mobile creates a funnel that desktop-first competitors can't replicate. As they now expand to Windows and eSIM, they can up-sell a premium desktop experience to an already-trusted mobile user base.
“Our biggest channel for growth even to send them to make them start using Windows is through our big mobile user base. We'll spend a lot of time on product marketing within mobile.”
Grow Across Platforms by Cross-Selling to Your Existing Mobile Base — Don't Start Cold
When Super Unlimited launched Windows, they skipped cold-start acquisition entirely and marketed the new platform inside the app to existing mobile subscribers. The logic: a billion-download install base of privacy-conscious users is the most qualified audience for a VPN on any new platform. Tanuj applies the same logic to eSIM — rather than buying airport ads, they target cohorts of known travelers within the existing app. Cross-platform growth as in-product upsell is their structural advantage.
“Our screenshots you know they're a bit stale. We have tried modernizing screenshots and 80% of the time when we do A/B tests they lose. People just like to see what they were used to seeing.”
Stale Screenshots Win 80% of A/B Tests — Data Will Surprise Your Design Instincts
Super Unlimited ran extensive screenshot redesigns expecting modern gradients and bigger text to lift conversion — and lost 80% of those tests. Users consistently preferred the older, plainer designs they associated with the top-rated product they knew. Tanuj's lesson: in established categories with strong ASO position, changing visual identity to match trends is often a mistake. Let the data surprise you, and only ship the 20% of improvements the tests validate.