Permutive doesn't currently offer lookalike modelling as we find our segments are typically very large, but it is in our long-term roadmap.
Permutive Without Lookalike Modelling
Typically look a like audiences are used by publishers to increase segment sizes. Our ability to update segments in real-time means our segment sizes are typically between 2x and 10x larger than other DMPs'.
Our Roadmap for Lookalike Modelling
Lookalike modelling is in our roadmap. Specifically - taking declared attributes (e.g. age), and using behavioural data to infer the likelihood of other users having those attributes.