You are walking down your favorite beach. As the water laps at your toes, you kick back at the surf absent-mindedly. After all, your mind is still partly back at the office on your direct marketing program.

It’s not that it’s doing badly per se. It’s just not doing great. And it’s getting harder. Response rates are dropping and it’s costing more to get the gifts you are getting.

It’s at that point that you stub your toe. You assume that it’s a shell, but when you look down, it’s a bronze lamp. Being genre-savvy, you quickly rub the lamp and out pops the requisite genie.

“Greetings,” booms the genie. “I am the wonderful, glorious 10% genie. I can increase any of the major measures of your 100,000 new donors this year — gifts per donor per year, average gift, or retention rate — by ten percent. And those increases will continue across their lifetime. What is thy bidding?”

Which should you choose?

Retention rate. Because it compounds.

While this works for any set of assumptions, I’ve made the following ones to the baseline to make the numbers real-ish:

• Slightly better than industry average retention rates: 30% of first-time donors and 60% of multi-year donors.*
• Average gift at acquisition of $20 and an increase in average gift of 20% per year
• 1.5 gifts per year per donor.

In this baseline scenario, your 100,000 donors will bring in $3,110,817 over five years. Having a 10% increase in average gift or gifts per year is nice, bringing in an extra $311,082.

But in these scenarios, you end the five years with 3,888 donors. If you can increase retention by 10%, you have 6,262 left at the end of five years. Those donors bring in $820,889 over the baseline and over $500K more than the other 10% scenarios.

So you tell the genie you want to increase retention and walk away happy.

Here’s the problem: there is no genie.

You have to invest to make these improvements. And right now, we mostly invest in the other two scenarios. We increase the number of pieces we mail at great expense to try to get more gifts from those who have already given this year. And the number of A/B tests we do to try to eke out more from our average gifts are astounding.

Not that you shouldn’t invest here. You should. After all, this is coming from the guy who wrote the book on the science of ask strings.

But if you would pick retention as your goal from a genie, it should also be the goal of your investment.

And the good news is that it’s not impossible. It’s not even improbable. By listening to your donors and customizing your communications, you can make the 10% increase in retention from the genie look like the pittance it is.

So if you’d like to sign up for these blog posts (free of charge, of course) and other tips and tricks to increase your retention, please do here:

* Note from last week: this is actually a 70% first-time donor burn rate and a 40% multiyear burn rate; if you can reduce these burn rates by 10% rather than increasing your retention rate, the difference is even starker.