Yet another study has shown how going solar is contagious. That is, when Yale University and UConn researchers analyzed residential solar installation data in Connecticut, they found that solar installations became clustered in the same geographical area, and that was true regardless of the neighborhood’s income level.

But why?

In the words of the researchers, “The effect of nearby [solar] systems diminishes with distance and time, suggesting a spatial neighbor effect conveyed through social interaction and visibility.”

The key words there are “through social interactions and visibility.” Essentially, the researchers are saying that neighbors are seeing a solar installation across the street or next door and they’re either directly asking their neighbors about their installation, or the mere sight of it is making neighbors curious and looking into going solar.

If that’s all accurate—and I’m sure it is—residential solar marketers have to do everything in their marketing power to enable their customers to show off their solar installations and to talk about it. If they do that, then the cluster will only continue to spread from neighborhood to neighborhood.

With that in mind, here are just a few visible and word-of-mouth solar tools that should help “infect” neighborhoods where you install.

• Plant lawn signs. Some HOAs prohibit these, but if they’re allowed, lawn signs can be a very effective marketing tool, especially when the panels aren’t visible from the curb. Make them attractive and ask your customer for permission to place them on the front lawn during the installation…or perhaps even a few days longer. Be sure to fit in your name, logo, website, and telephone number.

• Host solar parties. Solar installers have borrowed this tactic from Tupperware parties and Avon. The idea is to offer a catered party to celebrate going solar. You pay for the soft drinks and pizza or BBQ and attend the event. At a certain point, with the homeowner’s permission, you can do a brief presentation to educate guests about the solar installation and its costs. Most often, installers offer the solar homeowner a fee for every friend who ultimately goes solar. Clearly, your customers should love the job you did, or they will not be open to any parties, let alone referring you. In fact, the opposite may be true.

• Have a referral program. Even if you never host a solar party, offer a $200 to $500 Thank You Gift to customers who refer a neighbor or friend that also goes solar with your company. If you’ve done a great job, your customers should refer you without any monetary gift, but other customers may see the program as a way to further reduce their upfront solar costs or as a way to make extra income. Write up some referral materials to explain how the program works and let customers decide. You can also offer to donate the referral fee to the charity of their choice, such as a school program or a child’s sports league.

• Write SEO friendly blog posts that include your customer’s neighborhood. You might think that a blog post is far removed from a neighborhood, but don’t forget that neighbors may not actually talk to each other about those new solar panels. Instead, they’ll search for “Your Town solar installers” on the web. If you’ve written a few blog posts that include those key words “Your Town” and “solar installers,” Google will reward you with first page search results, and you’ll be one of the first websites that your customer’s neighbors visit to find out about solar in “Your Town.”

• Have amazing customer service. You want to inspire word-of-mouth in the neighborhood about going solar, right? Then do something inspirational worth talking about. Perhaps it’s bringing treats to pets, or perhaps it’s doing free lawn care after the installation is done. Maybe it’s scheduling a series of onsite inspections during the first year for quality assurance. Whatever it is, be generous and be genuine to your company values and mission. Your customers will be impressed and tell their friends about how you sincerely cared about them and their home.

• Use door hangers and/or direct mail. You’re in the neighborhood already, so perhaps hire people to spread some door hangers around the neighborhood. Better yet, be less intrusive. Instead, buy a direct mail list for the neighborhood and include messaging that says that a neighbor (keep it anonymous) has recently gone solar and that solar is now affordable for people in Your Section of Town.

These are just a few ideas to getting neighborhoods infected with the solar bug. However you inspire the conversation, please be ethical, be creative, and always… UnThink Solar.

Tor Valenza a.k.a. “Solar Fred” is the founder and CMO of UnThink Solar, and the author of Solar Fred’s Guide to Solar Guerrilla Marketing. For more solar marketing info, sign up for the UnThink Solar newsletter or follow @SolarFred on Twitter.