Who Needs To Send This Much Mail?
Spam. That’s the first thing most people think of when they hear “one billion marketing emails per month.” Yet contrary to conventional wisdom, there’s nothing inherently evil about sending a billion messages a month. Some of the businesses that move a billion messages a month include ESPs, social networks (some move more than a billion a day for that matter), social gaming sites and large online retailers.
Any time you have a fairly large number of users (5-20 million) who receive multiple messages per day, or a really large number of users (40-50 million) receiving one message per day, you are heading into the billion messages per month territory.
What Are The Numbers?
So exactly how much mail are we talking about here? That will depend on sending patterns:
In a lot of high-volume environments the sending will be to a worldwide audience, resulting in round-the-clock sending with no significant bursts of traffic. In such an environment the hourly volume will be 1,000,000,000 messages divided by 30 days divided by 24 hours equaling 1,388,889 messages per hour (386 messages per second), assuming 30 days in a month.
In an environment with inconsistent hourly volumes, we have to allow for both an average hourly volume and a maximum hourly volume and then design our solution to address the maximum hourly volume.
We need to look at seasonal factors: Does your social network move a lot of extra messages around Mother’s Day? Does your dating site move a lot of extra messages around Valentine’s day? Does your web shopping portal do a lot of extra business around Christmas?
We need to look at growth: If you are sending a billion messages a month it is very likely due to successful growth of your user base, something which you certainly have no intention of slowing. Look at how you have grown your email volume so far and extrapolate it out for the next year or two (especially if you only get budget for your infrastructure every two years).
Let’s assume for the sake of this article that you have an average volume of one million messages per hour with a peak volume of two and a half million messages per hour during your busiest season. You expect to double your user base each year for the next two years. At the end of two years you expect to be sending ten million messages per hour, or 7.2 billion messages per month (I’ve seen just this kind of growth several times with customers and prospects).
You Will Need to Send In-House
A lot of senders start by using an Email Service Provider (ESP) for their sending and should do so: an ESP provides infrastructure and expertise to handle the details of sending email marketing messages for their clients at a good price, allowing companies to focus on their business. In addition, the costs of installing and maintaining proper sending infrastructure and practices are not justifiable for most low-volume senders.
That said, if you are aiming for a billion email marketing messages a month and are still using an ESP, it’s time to plan your move to in-house sending. Assuming a $1.00 CPM (Cost Per Mille with Mille being Latin for thousand, so cost per thousand) you are looking at paying an ESP a million dollars a month to handle this kind of volume. Naturally you can probably secure a better rate than $1.00 CPM at these volume levels, but regardless of the discount: at this volume level it is certainly going to cost less to buy the infrastructure and hire the people needed to do this yourself, not to mention gaining the control you need when sending at these volume levels.
Next in Part 2: The Importance of Reputation