Before building, create a research plan to validate user needs and benchmark competitors' adoption of group calling. Part A (survey): Draft 8–10 concrete survey items (exact question text + response scales) to uncover use-cases, ideal group size, willingness to invite, acceptable latency, and blockers; include at least two randomized vignettes (e.g., different UI/latency trade-offs). Specify sampling frame, recruitment method, and how responses will be linked to behavioral telemetry while preserving privacy. Part B (competitors): Without internal data, estimate a U.S. adoption rate within ±20% relative error. List specific signals and how to collect them (e.g., search trends, app store review mining, third-party mobile panels, web telemetry, WebRTC STUN/TURN traffic proxies, public earnings remarks), then outline a triangulation and calibration model translating signals into adoption estimates. State assumptions, bias risks, and validation steps (e.g., back-testing on known launches).