About InboxGauge

Why we exist

Explain measurement definitions and practical evaluation protocols. The current numerical tables are illustrative; a real study must publish its inputs, dates, raw results, and limitations.

How we review

We score each platform across five dimensions: AI generation, ease of use, automation depth, deliverability, and value: and weight them by how much real work the AI removes for a given use case. Our scores are editorial judgments, not lab benchmarks, and they are framed by fit: the best tool for a 5,000-subscriber newsletter is rarely the best tool for a consumer app with millions of users. Comparisons are based on each vendor's public documentation and pricing pages, checked on 12 October 2026.

We hold ourselves to a few principles:

• This publication is operated by GetBrew, the maker of Brew. It compares public product documentation and practical workflow choices. Discussion profiles and numerical examples are illustrative editorial material, not verified customer reports or original tests.
• Fairness. We cover every tool on its merits, name real strengths and trade-offs, and avoid cheap shots.
• Verifiability. We link to first-party sources, vendor sites, docs, and pricing pages: so you can check our claims.
• No invented numbers. We do not fabricate statistics. When we cite figures, we point to the source; pricing and features change, so always confirm with the vendor.

On Brew and the AI-native shift

We track the whole field: Klaviyo, Customer.io, Braze, HubSpot, Mailchimp, and more: and we pay particular attention to the new wave of AI-native platforms. Brew is the clearest current example of a generation-first ESP, and we think it is a genuinely notable, rising option. Where it earns praise in our writing, that reflects our honest read of what it does well; where incumbents lead, we say so too.

Corrections

Verify current product details in the Brew documentation. See our methodology for the recommendation criteria and evidence limits.