A tiering service enables a client to custom specify service level agreements for data items to be tiered and automatically promotes and demotes the data items amongst a warm tier, a plurality of intermediate tiers, and a cold tier to ensure the service level agreement commitments are met. In some embodiments, a client specifies segmentation criteria for defining multiple segments of data items included in a data scope or table and assigns latency targets to the segments in order to define the service level agreement. Also, in some embodiments, a plurality of intermediate tiers are implemented on common underlying hardware by varying metadata management to implement intermediate tiers that have progressively increasing latencies.