When talking with marketers about email segmentation, the first question is generally around the conversion funnel. Bottom line, how will this affect my revenue per send?

The answer, as is often the case - is that it depends. It depends on how much we use the tool, the size of the segments, the criteria used. And that discussion is for another post: So what's behavioral segmentation worth anyways?

Now don't get me wrong - opens, clicks and conversion metrics in email will continue to be at the forefront of marketers' minds for some years to come. But the following will illuminate how the trends show that engagement metrics are equally important.

The Landscape

Consider this: According to the Global Email Deliverability Benchmark Report, Inbox Placement Rates (IPR) have declined to 76% from 81% in the second half of last year (2011). Furthermore, when you take out the uber sensitive and best of best email marketers from that group, only 71% of opt-in email makes it to the inbox. 

Why? MediaPost wrote a great blog on the stats and implications, and suggested that good content and subject lines were not enough to get your emails delivered. Rather, it described how subscriber engagement and feedback, sender scores, and reputation are far more important when determining if email makes the inbox. 

The Solution

And so therein lies the hidden benefit of behavior segmentation. When you start to use tools that target folks based on implicit behavior, good things happen. First, users are more likely to open that email. They're less likely to dreadfully "MARK AS SPAM". When other marketing emails are sent, shoppers will be more likely to engage with those messages because of the relevancy from others.

And so at the end of the day, behavioral segmentation goes far beyond influencing your conversion funnel for that particular campaign. The hidden benefit of email segmentation ultimately means increased engagement metrics, subscriber tolerance, and more emails making it to the inbox.