1. Overview
Every vendor receives a TrustScore from 0 to 100, computed from three components plus a volume bonus:
60
Review Aggregate
Bayesian-adjusted weighted average of Trustpilot (2×) and Google Reviews (1×) star ratings, scaled to 60 points.
20
Refurb Transparency
Grade descriptions, battery health disclosure, warranty clarity, returns policy quality. Max 20 points.
20
Operations & Legitimacy
BBB accreditation, US physical operations, contact information, years in business. Max 20 points.
+ Volume Bonus (up to +10 pts)
Vendors with higher verified review counts earn bonus points. Formula:
(vendor reviews ÷ total reviews) × 10.
TrustScore = Review Aggregate (0–60)
+ Refurb Transparency (0–20)
+ Operations & Legitimacy (0–20)
+ Volume Bonus (0–10)
= 0 to 100
+ Refurb Transparency (0–20)
+ Operations & Legitimacy (0–20)
+ Volume Bonus (0–10)
= 0 to 100
2. Bayesian Rating Adjustment
Raw star ratings are not used directly. Each rating is Bayesian-adjusted to correct for sample size bias — the same technique used by Amazon, IMDb, and Netflix.
The Bayesian formula
Adjusted Rating = (n × raw_rating + K × prior) ÷ (n + K)
Where:
n = number of reviews for this vendor
raw_rating = observed star rating (e.g. 4.7)
K = 5,000 (prior weight — equivalent "virtual" reviews)
prior = 3.5★ (market mean — neutral starting point)
Where:
n = number of reviews for this vendor
raw_rating = observed star rating (e.g. 4.7)
K = 5,000 (prior weight — equivalent "virtual" reviews)
prior = 3.5★ (market mean — neutral starting point)
How to read this formula
When a vendor has very few reviews (n ≪ K), the adjusted rating is pulled strongly toward 3.5★ — reflecting our uncertainty. When a vendor has many reviews (n ≫ K), the adjusted rating stays close to the observed rating. K = 5,000 means we need roughly 5,000 reviews before we give full weight to the observed rating.
Worked example: Sweetwater vs Reverb
| Step | Reverb | Sweetwater Gear Exchange |
|---|---|---|
| Raw Trustpilot ★ | 4.0 | 4.8 |
| Review volume | ~15,000 | ~12,000 |
| Bayesian TP adjustment | (15,000×4.0 + 5,000×3.5) ÷ 20,000 = 3.88★ | (12,000×4.8 + 5,000×3.5) ÷ 17,000 = 4.44★ |
| Raw Google Reviews ★ | 4.3 | 4.9 |
| Weighted avg (TP×2 + GR×1) ÷ 3 | 4.01★ | 4.45★ |
| Review score (÷5 × 60) | 48.1 / 60 | 53.4 / 60 |
| Transparency + Ops | 14 + 14 = 28 | 17 + 17 = 34 |
| Final TrustScore | ~77 / 100 | ~92 / 100 🥇 |
3. Component Detail
Review Aggregate (max 60 pts)
We combine Trustpilot and Google Reviews star ratings using a weighted average, with Trustpilot carrying 2× the weight per review. If only one platform has data, that platform's Bayesian-adjusted score covers all 60 points.
Weighted avg = (Bayes_Trustpilot × 2 + Bayes_Google × 1) ÷ 3
Review Score = (Weighted avg ÷ 5) × 60
Review Score = (Weighted avg ÷ 5) × 60
Refurb Transparency (max 20 pts)
Grade descriptions (A/B/C or equivalent): 0–6 pts
Battery health disclosure: 0–4 pts
Warranty terms (length + coverage): 0–4 pts
Returns policy (timeframe + conditions): 0–4 pts
Refurb process transparency: 0–2 pts
Battery health disclosure: 0–4 pts
Warranty terms (length + coverage): 0–4 pts
Returns policy (timeframe + conditions): 0–4 pts
Refurb process transparency: 0–2 pts
Operations & Legitimacy (max 20 pts)
BBB accreditation & US business registration: 0–6 pts
US physical operations: 0–5 pts
Published contact (phone/email/address): 0–4 pts
Years in continuous operation: 0–3 pts
Active social & support channels: 0–2 pts
US physical operations: 0–5 pts
Published contact (phone/email/address): 0–4 pts
Years in continuous operation: 0–3 pts
Active social & support channels: 0–2 pts
Volume Bonus (up to +10 pts)
Volume Bonus = (vendor_review_count ÷ 1,200,000 total) × 10
4. Sentiment Bands
≥ 86
🏆 Top Rated
Exceptional review scores, strong transparency and verified US operations.
70–85
✅ Rated
Good track record with some limitations in review volume, transparency or operations.
< 70
⚠ Fair
Below-average review sentiment, limited transparency, or marketplace-model vendors.
—
🔲 Unrated
Insufficient review data to compute a reliable score.
5. Data Sources
🟢 Trustpilot
Primary review platform. Carries 2× per-review weighting due to stronger identity verification and anti-fraud systems. Minimum 20 reviews required for inclusion without warning.
🔵 Google Reviews
Widely-used US consumer review platform. Carries 1× weighting. Provides broad consumer sentiment across the US market.
🏛 Better Business Bureau (BBB)
Used to verify business legitimacy, accreditation status, and complaint history for all assessed US vendors.
🌐 Vendor websites
Assessed directly for transparency components — grading descriptions, battery health disclosure, warranty and returns policies.
6. Important Notes
⚠ Whole-platform scores
Some ratings reflect whole-platform scores — not just refurbished products. For example, Amazon, Walmart, eBay and Best Buy reviews cover all products sold on those platforms, not exclusively refurbished items. Treat scores for marketplace-model vendors with extra caution.
⚠ Point-in-time snapshot
Review data is captured periodically and may not reflect the most recent reviews. Vendor policies are checked at time of scoring and may have changed. Always verify current terms directly with the vendor before purchasing.
ℹ Information only — not advice
RefurbVerify TrustScores are compiled for information purposes only and do not constitute purchasing advice, financial advice or endorsement of any vendor. See our full disclaimer & terms.
Methodology version: v1 (Bayesian-adjusted) · Launched 2026
Review sources: Trustpilot (2× weight) + Google Reviews (1× weight)
Score recomputed:
Review sources: Trustpilot (2× weight) + Google Reviews (1× weight)
Score recomputed: