Hi Lukas, one way that I've worked around the limitations of the segment filters is to add people to a list (static, not smart list) once they do x activity. "Member of list" is one filter that you are able to use for segmentations, so maybe if they open x number of emails in y number of days, you could have a smart campaign that would add them to the list and then they could be a part of the high open rate segment. I would also make sure to have a separate smart campaign (or wait step in the original campaign) that would remove them from the list after a certain amount of time or after a certain criteria is met so that they aren't in that high open rate list forever.