Brooks’ Law and Email Marketing

Our own Carissa Newton, tweeting from the EEC conference in Miami, mentions a case study presentation in which it was mentioned that Publisher’s Clearing House improved their email marketing ROI by removing inactive subscribers from their mailing list and divided the remainder into “actionable” segments for targeting.

I’m not at the conference, so I don’t have all the details, but I’m not surprised by the result.  It’s a great example of a paradox–that which runs counter to our intuition and so seemingly can’t be true, but is.

In my field of software development the most famous paradox is known as Brooks’ Law.  Joel Spolsky recently explained it in his Inc. magazine column:

The cost of overcommunication within organizations was fleshed out by Fred Brooks in his 1975 book, The Mythical Man-Month. Brooks helped run the OS/360 project at IBM, building a giant operating system for the company’s mainframes. In those days, computers were large, room-size, water-cooled machines, sometimes with a massive 256,000 bytes of main memory. OS/360 was probably the largest software project ever attempted to that point. And it was monumentally late.

Every time some aspect of the project fell behind schedule, IBM assigned a few more people to the task. And what Brooks noticed, which still surprises people, is that this didn’t work. His observation came to be known as Brooks’ Law: Adding people to a late project tends to make it run later still.

Read that sentence again, because it’s not intuitive. Brooks discovered that adding people to a project will put it further behind schedule.

The reason it doesn’t work to add people to a project is because adding resources also adds communication overhead.  A team of one person has zero communication overhead.  A team of two only has to communicate with each other.  Each new person added to the project has to be brought up to speed and put in communication with the other team members, to make sure their efforts are coordinated.  Soon, the hoped-for productivity gains of adding new people are erased by the overhead of keeping them all on the same page.

Adding people to a late project seems like it should get the job done faster, but it doesn’t.  Email marketing is very similar: it seems like you would get the maximum ROI by mailing the maximum number of recipients.   But the more addresses you mail, the greater the likelihood that you’re mailing uninterested recipients whose lack of engagement will affect how the ISPs prioritize delivery of your mail.  And the more you send to disengaged recipients, the more likely they are to hit the “Report Spam” button, damaging your deliverability further.

So what if you mailed fewer people?  What if, instead of sending a “blast” intended to appeal to the lowest common denominator among the gazillion subscribers who ever signed up for your email, you focused on those who actually still seem to interact with your mailings, and tested to find out how you can most effectively target them based on their demographics and behaviors?

It wasn’t a popular idea with PCH’s salespeople, reports Kristin Hersant.   And it won’t be popular with yours, either.  Heck, it’s not always popular among my own salespeople here at Delivra, since we’re paid based on the number of emails that you send.

It’s unpopular because it’s not intuitive.  But just because an idea isn’t intuitive, doesn’t make it wrong, as Fred Brooks demonstrated to software engineers over 30 years ago.

Chris Broshears | Product Development