What metrics would you use to evaluate a new WhatsApp feature for advertisers

Problem Statement Description

Product context: Meta is a social technology company; its products include Facebook, Instagram, WhatsApp, Messenger, Threads, Quest, creator tools, and ads. WhatsApp is Meta's messaging platform; its products include private chats, groups, calls, communities, channels, business messaging, payments in some markets, and status updates.

Meta is considering a new WhatsApp feature aimed at advertisers, likely helping businesses reach, engage, or convert customers through WhatsApp’s messaging and business ecosystem. Your task is to define how you would evaluate whether this feature is successful using a clear metrics framework.

This is a metrics interview question, so focus on what success means for advertisers, users, WhatsApp, and Meta’s broader ads business. The feature may touch sensitive surfaces such as private messaging, business conversations, click-to-message ads, customer support flows, or commerce interactions, so the measurement approach should balance advertiser value with user trust and platform health.

Your response should clarify the feature’s objective, identify the core user and advertiser workflows, define a primary success metric, and explain supporting metrics, guardrails, instrumentation, cohorts, and decision-making use cases. Avoid jumping straight to a list of metrics without explaining why each one matters and how it would be measured.

The experience should consider:

- The advertiser goal being served, such as lead generation, customer acquisition, remarketing, support, or conversion.

- The end-user journey from ad exposure or discovery into a WhatsApp interaction and any downstream action.

- A clear numerator and denominator for each key metric, including where the event is captured.

- Funnel metrics across impression, click, conversation start, response, qualified lead, conversion, and retention where relevant.

- Advertiser cohorts such as small businesses, large brands, verticals, geographies, budget tiers, and new versus existing advertisers.

- User trust and safety guardrails, including spam, unwanted messages, blocks, reports, opt-outs, and message quality.

- Business impact metrics that connect the feature to ads revenue, advertiser ROI, budget growth, and long-term advertiser retention.

- Instrumentation challenges such as attribution windows, privacy constraints, cross-surface tracking, and offline or third-party conversions.

The goal is to present a measurement plan that would help Meta decide whether the WhatsApp advertiser feature is creating durable value without harming the user experience or the integrity of the messaging platform.