As of late, we have been insanely focused on deliverability around here, and really, so should every org if they use email as a primary method of engaging prospects.
One way that we have approached deliverability is through engagement. We really only want to send tho those who are engaged with our website content, emails, etc., and we know Marketo is great at tracking this sort of activity, but let's be honest, you don't want to add all of these filters to each of your send list generators. In addition, we really don't want to be sending to records in our database that have done nothing. Let's say you got a list from an event or you purchased one and sent them emails, but a majority of them didn't open; what do you do with those? I am not saying that you can't email them every again, but you definitely don't want to keep sending to them when they are not engaging. This is for a couple reason, the obvious one is that they don't care about you and are clearly not interested, and the second is that no engagement negatively impacts deliverability.
So to quickly identify those we want to send to and to make this more efficient, what we've done is take what Marketo gives us in the activity log and aggregate it into a field we called the "Engagometer." We have five smart campaigns running in the background listening for activity: website visits, email opens, clicks in email, form fills, etc.
Here's how we grouped records:
We use this in tandem with Email Verification statuses: Verified and Unverified. Here's an example of how we build out a smart list for sending to:
From here you can add other criteria that you would normally filter by, but this is what we use as the base for all of our sends. We have seen our inbox placement and engagement increase dramatically from implementing this in tandem with the email verification tools.
I hope this helps someone out there. I'd be happy to answer any questions, too.
Interesting. We do something similar with an "Interesting Moments" scoring field. Since our IMs are already defined as the key engagement types/activity, we figured it was the best indicator without creating a bunch of new trigger campaigns (and just include an additional flow step to increase the score).
I would argue that email "opens" should not be an indicator of engagement. Furthermore, it's a very unreliable metric. Opens is not a KPI in any of our reports.