Early on, the product started with just the basics—asking users to connect with each other with big blue buttons that said "connect." But it was clear from the data that making connecting a primary action would spur engagement throughout the app—and so it became a central action. New users were asked to import their email contacts to invite more people. After each connection request, users were shown screens of even more suggestions. New users who appeared in other people's contacts—even if they skipped importing it themselves had suggested connections right after sign-up. The web of connections was mined to suggest "People You May Know" a feature still in use today that helps build density of networks, thus driving strong network effects. All of these tactics helped amplify growth. The denser the LinkedIn network, the more likely it was for new users to have a great initial experience.

No one wants to live in a ghost town. No one wants to join an empty community In the early days, it was our job each day is make sure there was good content on the front page. We'd past it ourselves, using dozens of dummy accounts. Otherwise the comma mity might dry up.

The older dating sites made it feel like you were doing work, like you were inside the office, You'd go and do work emails during the day, then go home and write more messages at night. Only to prospective dates rather than work colleagues. Tinder was different - it mule dating fun. You could sign up without filling in a bunch of forms. It's visual, you just swipe back and forth, and you could take foe minutes to do it while you were waiting in line or something like that. I's a form of entertainment.

The hardest problem to solve in creating the first atomic network is, well, attracting the hard side. Focus on attracting content creators to a new video platform, or sellers to a new marketplace, or the project managers inside a company to a new workplace app. The other side uf the network will follow.

Disruptive technologies are dismissed as toys because when they are first launched they "undershoot" user needs. The first telephone could only carry voices a mile or two. The leading telco of the time, Western Union, passed on acquiring the phone because they didnt see how it could possibly be useful to businesses and railroads-their primary customers. What they failed to anticipate was how rapidly telephone technology and infrastructure would improve (technology adoption is usually non-linear due to so-called comple. mentary network effects). The same was true of how mainframe companies viewed the PC (microcomputer), and how modern telecom companies viewed Skype. The next big thing will start out looking like it's for a niche net

The solution to the Cold Start Problem starts by understanding how to add a small group of the right people, at the same time, us-ling the product in the right way. Getting this initial network off the ground is the key, and the key is the "atomic network"_ the smallest, stable network from which all other networks can be built.