How Inbox Placement Rate (IPR) affects your ROI

Your open rate, click-through rate, bounce rate, unsubscribe rate and conversion rate are all key metrics that you can use to measure the success of your email campaigns and your ROI. But what if I told you that there is a new metric available to you that will greatly affect the way that your ROI is calculated? It’s called the “Inbox Placement Rate”.

Before diving into what drives the calculations, let’s take a look at some of the terms used today that are often misunderstood or applied incorrectly, the deliverability rate, delivered rate and accepted rate.

Deliverability rate
The term deliverability is very confusing with many people bandying around different definitions, amongst the confusion the term is even less accurate when one wants to know which mail actually gets delivered to the inbox. In my mind the word deliverability means exactly what it says, your ability to deliver and reach your client. Deliverability has become a profession, a concept, a strategy and for most senders another burden that stands between them and the (profitable) relationship with their clients and subscribers. Because there are so many other meanings to the word it is not the best term to use when talking about the number of emails that have reach the inbox.

Delivered (or delivery) rate
Often what is meant here is a basic calculation of the number of emails that have been sent subtracting those messages that bounced. We could also say “all the emails that have been accepted” by the receiving mailserver. ESPs often use this term to tell their clients that their delivery rate is above 95%. It is somewhat misleading to call this figure a true delivered rate as not all receiving mail servers send back consistent error or bounce codes.

Accepted rate
The accepted rate is defined as any message accepted during the SMTP session (minus the mail that is blocked due to policy, blacklisting, or content). It is similar to the delivered rate above.

Inbox Placement Rate
The wordings are simple to understand and, for me it clearly states the number of emails that have been placed in the inbox by the receiving party or ISP. So how does this impact your ROI calculation? Here’s how:

Take a look at the following table:

Metric	IPR 100%	IPR 50%	IPR 25%
Emails sent	100000	100000	100000
Emails bounce	10000	10000	10000
Emails delivered	90000	90000	90000
Delivered rate %	90%	90%	90%
Emails placed in Inbox	90000	45000	22500
Inbox Placement rate %	90%	45%	22,50%
Emails placed in Junk/Bulk	0	45000	67500
Junk/Bulk Placement rate %	0%	45%	67,50%
Emails opened	20000	10000	5000
Open rate %	22,22%	11,11%	5,56%
Emails clicked	4000	2000	1000
Clickthrough rate %	4,44%	2,22%	1,11%
Conversion rate %	2%	2%	2%
Average € per Order	25 €	25 €	25 €
ROI	2 000 €	1 000 €	500 €

If, as identified by the 2nd column, the Inbox Placement Rate would be 100%, the sender would get the best result from their email campaign. However, if they had lost 50% of their IPR (3rd column), then they would correspondingly also lose 50% of your ROI. Sounds logical right?

Based on numerous studies, 20% of all permission email never reaches the recipient (or inbox). This means that, if we use the table above, a sender/marketer sending 100,000 emails could lose as much as 400 Euros on each email campaign (assuming you earn 25Euro per order – but it could be higher!).

It is for these reasons that, in addition to the usual open, clicks, bounce metrics, savvy service providers around the globe are more frequently talking to their customers (the senders) about how Inbox Placement data can give far greater visibility into actual ROI and that calculations made without access to this data are fundamentally flawed. Whilst only some service providers have the capability to do so it is my strongly held belief that very soon clients are demanding this from their service providers.