{"id":2107,"slug":"spiegel-2017-five-reviews-270-percent-lift","title":"Spiegel 2017 (Northwestern) — 5 reviews = 270% purchase likelihood lift; 380% for higher-priced","kind":"reference","scope":"business","status":"current","audiences":["kevin","candid-team"],"topics":["review-revenue-causal-evidence"],"reference_body":"**Claim:** Northwestern University Medill Spiegel Research Center study (June 2017, with PowerReviews; research director Professor Edward Malthouse) found:\n\n- \"The purchase likelihood for a product with **5 reviews is 270% greater** than the purchase likelihood of a product with no reviews.\"\n- Higher-priced/higher-consideration products: displaying reviews raised conversion **190% for a lower-priced product but 380% for a higher-priced product**.\n- \"When the price is higher, there is more risk involved in the consumer's decision.\"\n\n**Source:** Spiegel Research Center, Northwestern University. **Academic.**\n\n**Confidence:** Verified.\n\n**Why this matters for Candid:** Independent corroboration of Luca's effect in a different research design + domain. The 380% figure for higher-priced products is particularly relevant for trades / professional services / B2B.","rationale_body":null,"metadata":null,"links":{"outgoing":[],"incoming":[{"slug":"research-brief-smb-widget-market-difficulty-june-2026","title":"Research brief: SMB widget market difficulty — six ranked factors (June 2026)","kind":"reference","scope":"business","link_type":"relates-to"},{"slug":"reviews-as-conversion-moat","title":"Factor 5 — Trust/review moats (conversion, not just ranking)","kind":"reference","scope":"business","link_type":"depends-on"}]},"created_at":"2026-06-23T19:16:04.244Z","updated_at":"2026-06-23T19:16:04.244Z"}