Sierra

Sierra is what happens when the former co-CEO of Salesforce decides customer service is an agent problem. Bret Taylor and Clay Bavor's company builds branded AI agents that handle chat and — impressively — voice conversations for enterprises like ADT and SiriusXM, taking real actions in backend systems rather than reciting help articles. The signature move is outcomes-based pricing: you pay when the AI resolves a conversation, not per seat or per message.

What we like

Voice is where Sierra separates from the pack. Its phone agents handle interruptions, accents, and mid-call topic changes with a fluidity most competitors haven't matched, which matters because phone remains the most expensive support channel to staff. The outcome pricing model deserves credit for honesty — the vendor only gets paid when the product works. And the supervision tooling reflects enterprise reality: guardrails, QA workflows, and behavioral monitoring are first-class features, not afterthoughts, which is exactly what a brand-conscious CX executive needs to sleep at night.

Where it falls short

This is an enterprise sales motion with everything that implies: no public pricing, months-long procurement, and implementation projects. Per-resolution pricing, while well-aligned, makes budgeting genuinely difficult at scale — success gets expensive. The platform is also young; its integration catalog and community knowledge trail incumbents like Zendesk or even Ada.

Verdict

If you're an enterprise brand with heavy phone and chat volume and budget to match, Sierra should be on every shortlist — it's arguably the most technically ambitious player in the space. Everyone else should admire it from a distance: mid-market teams get better value from Ada, Forethought, or their help desk's native AI.