In some embodiments, a method analyzes a characteristic of a segment list for a user identifier, and compares the characteristic for the segment list to two or more thresholds. A storage type is determined for the segment list based on the comparing. A value for the segment list is stored using a storage type from a plurality of storage types based on the characteristic for the segment list meeting a threshold for the storage type from the two or more storage types. The method stores the value for the segment list in storage, wherein the value is stored based on the storage type.