Tools like ActiveCampaign and Infusionsoft have the ability to apply tags to subscribers. The tags are not only for segmentation purposes, but can trigger events or flows. This would be VERY useful. The guys at GroundHogg have this figured out. They are ex-Infusionsoft and I guess they have taken the concept further . Check it out!
TAG subscribers in one list. Segmentation is good, but yet you get the same subscriber in every list you segmented. The idea of TAGGING is one list and give subscribers flags = TAGs to filtering and selecting for special interessts and letter, mostly in a automated way.