Having helped scores of nonprofits build their e-mail list while at Care2.com, I have a healthy appreciation for how important e-mail lists are to nonprofits. Many rely on them as the foundation of their online fundraising and advocacy efforts. They're still the best online fundraising tool available, even in the age of Facebook. And for many nonprofits, sharing their list with another cause is a scary idea. Why risk eroding hard-won support by giving another cause a crack at your donors?

According to a new study by nonprofit consultancy M&R Strategic Services, turns out sharing e-mail lists is a smart strategy that leads to net gains in advocacy and fundraising for both nonprofits involved.

Here's how e-mail list sharing works. Unlike direct mail list swaps, you don't actually turn over e-mail addresses to another cause. Instead, you send a message to your list on behalf of your partner and they do the same for you. Both parties negotiate the timing and content of messages so that the respective messages are relevant thus well received.

In the study, the League of Conservation Voters (LCV) sent an action alert to their list on behalf of The Wilderness Society (TWS). In the e-mail sent, LCV introduces the action to its subscribers with the TWS alert below. The TWS alert asks readers to click on a link to send a letter to the government.  When readers click, they land on a TWS page with the letter. The letter includes an opt-in check box to join WS' e-mail list. If the LCV list member checks this box when signing the TWS letter, then they join TWS' e-mail list. TWS did the same thing for LCV.  Both causes grew their e-mail lists at little to no cost by sharing.

And the results? Astounding. Two years after the trial cross promotions, "the LCV and TWS supporters who participated in the cross promotion are actually more likely to take action for the original nonprofit than they were before the cross promotion took place." This means that sharing lists benefits both nonprofits and increases the overall activism of collective list members. And what about the fear that sharing lists would hurt fundraising? The study found no evidence that cross promotions had a negative impact on giving. While response rates to appeals did not go up, both organizations benefit because they have more people from whom they could raise money.  

So in this case, everyone wins – both nonprofits grow their support base, list members benefit from increased civic participation, and citizen engagement increases in society. Imagine what would happen if every nonprofit shared their list?  It's my guess that we'd be that much closer to a civic instead of a consumer culture.

The study also offers these six simple steps for effective cross promotions.  Check the study for more detailed instructions.

• Find a partner group with a similar mission.
• Decide on an action
• Draft a written agreement with your partner
• Dedupe our lists
• Draft the alert copy
• Set up alerts, share tests, and launch
• Recruit new subscribers

Oh, given the topic and being a 501(c)3 nonprofit ourselves, I have to ask, if you want to join Shareable's e-mail list to get our weekly top story update plus the occasional you know what, go here.