Say, you've just finished making a great new website. You've built a contagious message, so that people will share it, but you only have enough money to diffuse it to a certain set of your target demographic. Should you spend all your money targeting one group? Should you spread it out? And within that group, who should you target and why? Should you pick people that are popular, maybe that have a lots of friends? Or people that have the right positions in the social network and might connect you to other individuals in different networks. One way to think about this is the sprinkler or waterfall strategy. A waterfall strategy is when you concentrate all your marketing efforts in one place, or one region. If you're the United States, for example, you might pick a given city to start in. Concentrate all your resources there and hope to spill over into the nearby cities moving on. A sprinkler strategy is when you spread out your resources to different areas. Rather than concentrating 100% in one city, you might spend 10% in each of 10 different cities. Which of those things might be more effective and why? We can think about reasons for both. The benefit of the sprinkler strategies are spreading it out, you're starting many seeds in many different communities. That could be good, because it could get it to catch on faster in different networks, but a waterfall strategy could also be good if people need multiple doses of influence before they adopt something. And so one way to think about whether to use a sprinkler strategy or a waterfall one is to understand whether that product, that you're hoping to catch on is a simple or complex contagion. A simple contagion is something that you only need one dose of influence before you're willing to adopt. Take, for example, a newspaper article that someone might send to you online. You didn't need to hear about that article from five or six people before you're willing to open the link. One person's enough for you to check it out. A movie takes a couple more doses of influence. You might not just go see a movie, because one person said something about it. But if a few people say something about it, you'll check it out. And on a much more complex end of the spectrum say, someone suggested a new open heart procedure. You wouldn't just need one person to tell you about it before you'd try it, you wanna do lots of research before you're willing to try that risky procedure. So complex contagions require more doses of influence before you're willing to adopt, whereas simple contagions take fewer. Take, for example, a pickled pickle. You only need one dose of influence to try a brand of pickles. But if someone said try pickled broccoli, you might need to hear about it a few people before you're willing to try it out. So again, simple contagion are things that require only one dose of influence, whereas complex require multiple doses before people are willing to try it. Complex things tend to be more costly, whether in terms of time, effort or energy. The more money you have to spend doing something, the more you wanna gonna hear about it a few times before do it. Well, simple versus complex contagions have an important implication for whether you should use a waterfall of a sprinkler strategy. When you have a complex contagion, you need to use more of a waterfall strategy. When people need multiple doses of influence before they're willing to adopt, they're gonna need to hear about that product or service for multiple people before they feel comfortable, which means you need to make sure that multiple of their peers have heard about it to get them to change their mind. That suggests you need to concentrate your resources on geographic, demographic or social network region online. Making sure that indi people and individual area a subset of a network have heard about it multiple times. If you've got a simple contagion, if people only need one dose before they're willing to do it, well, then you can spread your resources out. People don't need to hear about it multiple times. And in fact, multiple times will waste some of your marketing resources. It's much better to spread them out, so that each person hears about it once. They hear about it from one other person that causes them to adopt it and that increases the likelihood it will catch on more quickly in the broader community. The more doses required for product adoption, the more you wanna concentrate your resources in one area. One geography, one social group or one set of people that has similar tastes.
