The Cold Start Problem: How to Start and Scale Network Effects

Flinstoning” is a metaphor for this car, except in software, where missing product functionality is replaced with manual human effort.

Success comes with an inevitable problem: market saturation. New products initially grow just by adding more customers—to grow a network, add more nodes. Eventually this stops working because nearly everyone in the target market has joined the network, and there are not enough potential customers left. From here, the focus has to shift from adding new customers to layering on more services and revenue opportunities with existing ones. eBay had this problem in its early years, and had to figure its way out. My colleague at a16z, Jeff Jordan, experienced this himself, and would often write and speak about his first month as the general manager of eBay’s US business. It was in 2000, and for the first time ever, eBay’s US business failed to grow on a month-over-month basis. This was critical for eBay because nearly all the revenue and profit for the company came from the US unit—without growth in the United States, the entire business would stagnate. Something had to be done quickly. It’s tempting to just optimize the core business. After all, increasing a big revenue base even a little bit often looks more appealing than starting at zero. Bolder bets are risky. Yet because of the dynamics of market saturation, a product’s growth tends to slow down and not speed up. There’s no way around maintaining a high growth rate besides continuing to innovate. Jeff shared what the team did to find the next phase of growth for the company: eBay.com at the time enabled the community to buy and sell solely through online auctions. But auctions intimidated many prospective users who expressed preference for the ease and simplicity of fixed price formats. Interestingly, our research suggested that our online auction users were biased towards men, who relished the competitive aspect of the auction. So the first major innovation we pursued was to implement the (revolutionary!) concept of offering items for a fixed price on ebay.com, which we termed “buy-it-now.” Buy-it-now was surprisingly controversial to many in both the eBay community and in eBay headquarters. But we swallowed hard, took the risk and launched the feature . . . and it paid off big. These days, the buy-it-now format represents over $40 billion of annual Gross Merchandise Volume for eBay, 62% of their total.65

Launching “Buy It Now” was a large change that touched every transaction, but the eBay team also innovated across the experience for both sellers and buyers as well. With an initial success, we doubled down on innovation to drive growth. We introduced stores on eBay, which dramatically increased the amount of product offered for sale on the platform. We expanded the menu of optional features that sellers could purchase to better highlight their listings on the site. We improved the post-transaction experience on ebay.com by significantly improving the “checkout” flow, including the eventual seamless integration of PayPal on the eBay site. Each of these innovations supported the growth of the business and helped to keep that gravity at bay. Years later, Jeff became a general partner at Andreessen Horowitz, where he would kick off the firm’s success in startups with network effects, investing in Airbnb, Instacart, Pinterest, and others. I’m lucky to work with him! He recounted in an essay on the a16z blog that his strategy was to grow eBay by adding layers and layers of new revenue—like “adding layers to the cake.” You can see it visually here: Figure 12: eBay’s growth layer cake As the core US business began to look more like a line than a hockey stick, international and payments were layered on top. Together, the aggregate business started to look like a hockey stick, but underneath it was actually many new lines of business.

acquiring the hard side of the network and keeping them happy is paramount to standing up an atomic network.

Once Hopkins showed that this worked in creating one atomic network, the effort could be repeated in building the second, third, and so on: We proved out this plan in several cities of moderate size. Then we undertook New York City. There the market was dominated by a rival brand. Van Camp had slight distribution. In three weeks we secured, largely by letter, 97 per cent distribution. Every grocer saw the necessity of being prepared for that coupon demand. Then one Sunday in a page ad, we inserted the coupon. This just in Greater New York. As a result of that ad, 1,460,000 coupons were presented. We paid $146,000 to the grocers to redeem them. But 1,460,000 homes were trying Van Camp’s Milk after reading our story, and all in a single day. The total cost of that enterprise, including the advertising, was $175,000, mostly spent in redeeming those coupons. In less than nine months that cost came back with a profit. We captured the New York market.

The other question to ask is, if a user wants to reactivate, how hard is it? At Uber, we had a staggering statistic where several million users were failing their password recovery per week—how do you make this much easier, and treat reactivation with the same seriousness as the sign-up process? While reactivation is typically not a concern for new products—they should focus on new users, since their count of lapsed users won’t be large—for products that have hit Escape Velocity, there will be a pool of many millions of users to draw upon. Reengaging them can become as big a growth lever as acquiring new users.

This is an important tool that is unique to networked products. Traditional products that lack networks often struggle with this, because they rely on spammy emails, discounts, and push notifications to entice users back. This usually doesn’t work, and company-sent communications rank among the lowest clickthrough rate messages. Networked products, on the other hand, have the unique capability to reactivate these users by enlisting active users to bring them back. Even if you don’t open the app on a given day, other users in the network may interact with you—commenting or liking your past content, or sending you a message. Getting an email notification that says your boss just shared a folder with you is a lot more compelling than a marketing message. A notification that a close friend just joined an app you tried a month ago is a lot more engaging than an announcement about new features. And the more dense the network is around a churned user, the more likely they are to receive this type of interaction.