The ability to manage multiple lists, create and manage multiple suppression lists that can be applied globally or per list or segment. The flexibility of delivering through several ESP / IP based on our own rules and preferences.
If you are in the emailing business then you know that no one single ESP will always have best deliver-ability, being able to direct traffic to our ESP of choice allows us to send traffic to the best performing ESP without having to move, migrate and change the lists in any way.
Prior to Ongage if we were unhappy with an ESP's deilverability it meant signing up with a new ESP and, exporting, re-importing the lists, and suffering lengthy onboarding process. With Ongage we maintain several ESP accounts so we are always warming IP's and ready to redirect traffic on a moments notice, literally with the flick of a switch.
Additionally, some ESP's can be very sensitive about list quality, with Ongage it's very easy to setup several ESP's and direct traffic to one or the other depending on list quality.
As an example we use a more lenient ESP to re-engage older leads, and move them over to another ESP once they are engaged. To do this we simply create 1 segment for un-engaged and 1 segment for engaged and tell Ongage which ESP to use.. We set it up one and it's set and forget. Review collected by and hosted on G2.com.