Jun 23, 2017 · 34m · y-combinator
Scaling Growth | Gustaf Alstromer, YC Partner (formerly Airbnb) & Ed Baker (formerly Uber) · Y Combinator
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In this ScaleUp Offsite growth panel hosted by Greylock Partners and Y Combinator Continuity, growth veterans Ed Baker (formerly Uber and Facebook) and Gustaf Alströmer (formerly Airbnb and Voxer), moderated by Josh Elman, discuss key strategies for scaling platforms. They share lessons on building cross-functional growth teams, optimizing North Star metrics, executing counterintuitive experiments, and managing channel saturation.
How this conversation actually went
Every chapter scored 0–10 on four independent dynamics. Hover any point for the reasoning behind the score. How this is scored →
The partners as informed peer 4.5 Guest teaching 5.7 Guest disagreement 0.0 The partners pushing back 0.2
speaking balance: gold is the partners, purple is the guest (3 minute bins)
Sharpest disagreement ▶ 20:14 Friendly challenge on missing Instagram ad opportunity
The overall panel is highly collegiate, but this moment features the sharpest divergence in perspective when Elman challenges the guests for overlooking Instagram's ad pricing advantage.
Hardest push from the partners ▶ 20:14 Elman calls out guests for overlooking Instagram adsElman directly offers an alternative view to the guests' broad long-term channel philosophy by bringing fresh tactical data from F8 regarding Instagram ad mispricing.
Biggest teaching moment ▶ 26:40 The Japan Facebook invite-to-announcement copy reframeEd Baker provides a masterclass on localization psychology, showing how shifting from 'invite' to 'announce' overcame cultural barriers to convert Facebook's worst viral market into its best.
The partners hold their own ▶ 20:14 Elman demonstrates insider growth intelligence from F8Josh Elman injects his own domain expertise into the panel, surfacing actionable ad pricing arbitrage intel directly from his conversations with Facebook engineers.
the scores for every segment, with the reasoning behind each
| Chapter | Topic | The partners as informed peer | Guest teaching | Guest disagreement | The partners pushing back | Why |
|---|---|---|---|---|---|---|
| Ed Baker on Early Facebook Viral Growth Hacks | 5 | 5 | 0 | 0 | Josh Elman frames the discussion around early viral growth on Facebook's platform, drawing on his own background there. Ed Baker shares the tactical exploit of the Zodiac Photo Album app tagging 240 friends per click, creating a collaborative trip down memory lane. | |
| Gustaf Alströmer on Mobile Growth Mechanics at Voxer | 4 | 6 | 0 | 0 | Elman asks about mobile experimentation at Voxer, noting mobile was considered much harder than web platforms. Gustaf Alströmer explains the core mobile loop around address book phone number matching and push notifications. | |
| Transitioning from Hacking to Mature Growth at Facebook | 5 | 6 | 0 | 0 | Elman prompts Baker on transitioning from hacking to Facebook's mature growth org. Baker explains the shift from acquisition to retention, noting friending (PYMK) was the primary retention lever and describing the five-function cross-functional structure. | |
| The Evolution of Growth Teams at Airbnb | 4 | 5 | 0 | 0 | Elman asks about porting growth methodologies into real-world offline industries like hospitality. Alströmer outlines how growth evolved from a standalone evangelist pod to an org-wide standard for metrics-driven decision making at Airbnb. | |
| Defining North Star Metrics & Real-World Friction at Uber | 4 | 7 | 0 | 0 | Baker defines North Star metrics in a two-sided marketplace, explaining why Uber chose weekly completed trips over simple active users. He illustrates real-world funnel friction with his personal story of getting cold feet before his first driver ride. | |
| Paid Acquisition vs. Organic Virality Strategy | 5 | 6 | 0 | 0 | Elman contrasts traditional VC skepticism toward paid marketing with modern marketplace dynamics. Baker and Alströmer detail how paid performance marketing was formalized as a technical discipline and how dynamic supply-demand constraints affect LTV calculation. | |
| Mastering Primary Growth Channels | 6 | 4 | 0 | 2 | When guests advise focusing on building a great product and long-term channel bets, Elman jumps in with a counter-suggestion citing real-time intelligence from F8 that Instagram app install ads are underpriced. | |
| Uber's City Expansion Playbook & China WeChat Onboarding Hack | 4 | 6 | 0 | 0 | Elman asks about scaling local growth playbooks versus centralized infrastructure. Baker shares how Uber engineered a dedicated WeChat onboarding bot in China to bypass mobile browser and firewall onboarding friction before getting blocked. | |
| Global Expansion, Translation, and Product Gaps | 4 | 6 | 0 | 0 | Alströmer breaks down internationalization into translation and product gaps, then explains Airbnb's bi-weekly experiment review ritual where teams vote on counterintuitive A/B test results. | |
| High-Impact Copy Tweaks: The Japan Facebook Case Study | 4 | 6 | 0 | 0 | Baker presents a case study from Japan where renaming 'invites' to 'announcements' transformed it from Facebook's lowest to highest viral market. In response to an audience member, Baker breaks down mathematical growth accounting across lifecycle S-curves. | |
| Audience Q&A: Driver Activation & Overcoming Onboarding Friction | 5 | 6 | 0 | 0 | Audience members ask about overcoming driver hesitation and resolving organizational tension between growth and product. Baker and Alströmer confirm both companies ultimately merged growth and core product orgs. |
Statements from this episode (23)
Elman: Airbnb's growth team expanded from 3 to over 100 people
“Ed joined Uber to start the growth team when it was five people, and then over the three and a half years became kind of VP of both product and growth for kind of all of Uber, and Gustav joined, and the Airbnb growth team was him and two other people when he g…”
Baker: Zodiac app tagged tens of millions in 24 hours before shutdown
“Within I think within 24 hours, we had tagged tens of millions of people in photos. I think including Zuck, and then I heard the platform team shut it down shortly after that.”
Alströmer: Growth disciplines become vital when new platforms emerge
“Growth kind of becomes important when they have new platforms. So you have Facebook platform, you have the mobile platform, you have Google, SEO, there's a bunch of larger platforms that makes people actually care about investing in them.”
Alströmer: Voxer user retention hinged on first-time friend count
“We found that the amount of friends that you have when you open the app that were the very first time on the app and how you display them was absolutely, absolutely key to whether they were going to use the app or not.”
Baker: Facebook's MAUs Were Driven More by Retention Than Acquisition
“Facebook was already at a size where retention and engagement were bigger drivers of the North Star metric MAUs than new user acquisition.”
Baker: Friending Was Facebook's Number One Driver of User Retention
“Most of the growth team at Facebook at the time was actually focused on friending, because we discovered at Facebook that friending was the number one driver of retention and engagement.”
Baker: Facebook's growth team reached around 500 people during his tenure
“And when I was at Facebook, I think the growth team was about, around 500 people or so.”
Baker: Facebook's entire analytics team was once part of growth
“In fact, all of analytics back then was part of the growth team.”
Baker: Uber chose weekly trips as North Star to balance supply and demand
“Ultimately we decided on trips, weekly trips as the North Star metric, because for every trip to take place, you need, ah, riders and you need drivers. And so by having trips as that North Star metric, you could then break that down into the supply side and th…”
Baker: Facebook Relied on Organic Growth While Uber Scaled Paid Acquisition
“So, Facebook, we didn't really do very much paid acquisition, but at Uber, we had an entire performance marketing team. Well, initially it was a one-person team, but ultimately became a team where we would actually spend money to acquire both riders and driver…”
Baker: Uber would have kept growing without any paid acquisition
“Uber would have kept growing even if we had never done any paid acquisition, but especially in a competitive market it kind of makes sense to pay up to what the, that rider or that driver is ultimately going to be worth”
Alströmer: Most companies achieve massive scale by mastering just one platform
“Most companies that go really, really large, they do it on figuring out one platform. So they are really good at online marketing, they're really good at SEO, they're really good at reality, or the Facebook platform, or something like that. It's rare that you …”
Elman: Facebook Insiders See Instagram App Install Ads as Significantly Underpriced
“The tip I got yesterday at F eight talking about to Facebook folks is they think Instagram app install ads are significantly underpriced relative to Facebook.”
Baker: Uber used a WeChat bot to onboard Chinese drivers until blocked
“One of the engineers on our China growth team built a WeChat bot. WeChat's, you know, like a mess, the messaging app, or the Facebook of, sorry, the Facebook, and also the Internet of China, really. And so we built this WeChat bot, Where, as a driver, you coul…”
Alströmer: Translation is an overlooked, major international growth driver
“One is translation. So, absolutely key to have a way that you can translate content across languages that's often overlooked, and it's like a huge growth driver.”
Alströmer: Only 5 to 10 countries are dramatically different from the US
“There are not that many countries in my experience that are dramatically different. There are maybe five or 10 that are quite different than the US, but most countries are not that different.”
Alströmer: Airbnb Held Bi-Weekly Experiment Reviews Where Teams Guessed A/B Test Winners
“Every two weeks, the growth team gets into a room, and we show experiments that we've shipped and gotten significant results on in the last, last month, say. And the engineer will go on stage, show the experiments, show the control and the experiment. Before t…”
Alströmer: Growth Teams Not Seeing Counterintuitive A/B Results Aren't Taking Big Risks
“Predicting product decisions are really, it's really tricky. So I would say this happens all the time, and if it doesn't happen, then you're not taking big enough risks. You should be seeing things that are counterintuitive.”
Alströmer: Websites Should Never Automatically Log Users Out For Better Growth
“If you have a website, and you have people come to your website, and you have accounts, don't log them out. Just like, keep people logging for as long as you can. There's really no benefit in automatically logging people out after, after a couple of months, af…”
Baker: Simple copy change made Japan Facebook's most viral market
“And Japan went from like our least viral country to our most viral country. But it was literally just a copy tweak to make people more comfortable with sharing what the product they were using with their friends.”
Baker: Uber tested phone mentoring by existing drivers for first-time trips
“We also experimented with are there ways we can get potentially existing drivers or other people to, like, get on the phone with a driver and talk them through that, that first that first trip.”
Alströmer: Airbnb Measures Data Team on Experimentation Tool Adoption
“At Airbnb, really the entire product team is now a growth team, and the goal of the data team that have built these tools is to get everybody to use them. Like, they're, Literally measured by how many people using experimentation frameworks.”
Baker: Uber Merged Core Product and Growth Teams in 2016
“We actually merged the product team and the growth team about a year ago at Uber for largely for those reasons. Especially as we started focusing more on engagement and retention within the growth team. And that's kind of what the core product team was working…”