I got a flu shot this year, like I typically do. Back in college, the flu shot saved me from a nasty flu-like illness that put dozens of students in the hospital, so it’s been an easy sell since then. But it always amazes me to see how stubborn some people are about getting the shot.

Even with all the PSA’s and other messaging out there, a lot of people don’t bother with flu shots. As I was thinking about this recently, I realized that vaccinations are sort of like any other network ecosystem. In other words, the value of the product to any one user (in this case, someone who got the shot) increases as more people use the same product (thus getting the shot themselves). Take email, for instance. The more other people have email access, the more useful your email account will be.

What does this have to do with vaccinations? It’s simple: the more other people get the shot, the less likely they are to get the illness. Fewer people with the illness means that you’re less likely to get it too. In other words, when other people stay healthier, it reduces the spread of disease and helps you stay healthier too.

So how can the folks in charge of flu shots take advantage of this? At a minimum, I’d like to see state-wide or nationwide programs that give coupons to everyone who gets the shot. They could then give these to friends, family, and coworkers to help them save money on getting the same vaccination. Or, beef up the messaging by cultivating testimonials from people who can give personalized stories of why they do it every year — or just got the vaccination for the first time. Either way, realizing and taking advantage of network effects for vaccinations would help keep everyone healthier.