There are any number of ways to acquire an email address.  Change.org or Care2 will run cost-per-acquisition campaigns with you.  You can do online advertising (paid or Google Grant-ed) that drives people to your site.  You can e-append your offline constituents in the hopes of further cultivating your relationship with them.  And there’s organic — getting people to come to your site, then getting to sign on the line that is dotted.

These all have one thing in common: they cost.  They cost in time, treasure or both.  So you need to know whether the effort is worth it.  And for that, you need to be able to put a price tag on a constituent.

This is anathema to some.  Witness our (fake) debate on whether we want more donors or better donors: there are some intangibles that are, well, intangible.

But we are judged against numbers.  Our goal is to raise money and make friends, in that order.  So let’s quantify what we can.

While we are attaching caveats to this, let’s also stipulate that you should do this exercise both for your average email address (since you won’t always know from whence your constituent came) and for as many subsegments as you can reasonable do.  The value of a Care2 advocacy person will be different from an organic advocacy person, which will be different from someone who is looking for information on your site, which will be very very different from an offline donor or a walk donor that you are working to make a multichannel or organization donor.  Each will have its own value and price.

So I’m going to describe the exercise for how you would do a generic email address; the principles are the same for any subsegment.

The first step is to determine the lifetime value of the person’s online donations.  Again, I’m going to eschew attribution modeling as very complex — do it if you can, but if you can’t, you are in the right place.

You might think, as I once did, that the way to determine this is to take the online donations you have for a year and divide by the number of email addresses.  However, this ignores that many of your donations are made by people who are not online constituents (and may never be).  So this estimate will be far too high.

You might think, as others I’ve seen do, that you can derive this by totalling the amount given by the amount given to ask emails throughout the year.  However, this ignores that your email may stimulate a desire to give that is fulfilled on another device, another day, and even by another method (more on that later).  Counting just donations given directly to emails will give you an estimate that is too low.

So those are the Papa Bear and the Mama Bear solutions; what does Baby Bear say is just right?  I would argue that you should count the donations given online by those who were signed up for and receiving emails at the time of their online gift.  This too will be an overestimate — you might have received some of those gifts if you didn’t have those folks as constituents.  However, it’s much closer than the Papa Bear model and, as you will see from having run your numbers on revenue per page from yesterday, a constituent gift is far more likely than a person-off-the-street gift.

You also need to factor in the lift that online gives to other channels.  I recently saw an analysis of an e-append that still has double-digit increases in both response rate and average gift of the mail donors four years later.  And this included people who had since unsubscribed.  So properly written and targeted emails can be a strong retention tool.

You can look at your file and see what the offline donation and retention rates are for people for whom you have email addresses and those who don’t.  The challenge is that these are likely to be different types of people.  You ideally want to compare someone to themselves before you had their email address as well as a control audience.

That’s why I like to look at e-appends of the past for this.  You can determine:

• Value of average donor before e-append who got appended
• Value of average donor before e-append who didn’t appended
• Value of average donor after e-append who got appended
• Value of average donor after e-append who didn’t appended

From that, you should be able to derive the lift that email itself gave.  (If you need the formula, email me at nick@directtodonor.com; it’s a bit boring to go through in detail here.)

Similarly, for events with online registration, the good news is that a lot of walkers fake their email addresses or don’t give you one.  How is that good news?  It gives you a nice experiment.  Take the people who gave you their emails versus those who don’t and their return rates and gifts given/raised amounts.  My guess is that being on your email list should increase both retention and value.  These too can go into the lifetime value hopper.

Now you have a formula to got back to your analysis of pages.  Maybe those advocacy participants of today are likely to be your donors of tomorrow.  Or maybe your Change.org advocates didn’t convert the way you would like in the long-term.  These will help you make choices around investments, pages, and people.  Hope it helps!