How we rank companies
Every company on DuctCompare carries a score out of 100. This page is the whole formula. If a directory will not show you this, the reason is usually that the answer is “whoever paid”.
Trust and certification
30/100Verified insurance carries the most weight of any single item on the site, because it is the only thing here we personally checked rather than accepted. NADCA membership, the number of certified ASCS technicians on staff, and whether the listing has an accountable claimed owner make up the rest.
Price transparency
25/100Publishing a flat price for a standard home, and defining what a standard home means to you, together carry most of this. Note carefully: the price itself is not scored. A cheaper company does not rank higher. Being willing to publish a comparable number is what ranks.
Profile completeness
20/100How much of the profile is actually filled in — equipment, source-removal methods, service ZIPs, description, photos, contact details. A company that will not tell you how it does the work is telling you something.
Reviews
15/100Deliberately the smallest component. Home-services reviews are thin, gameable and heavily selection-biased, so we weight them below things that can be checked. Ratings are also shrunk toward 3.8 using a prior of 8 reviews, which means a single five-star review from a friend moves the number very little.
Recently updated
10/100Decays over a year. A listing nobody has touched since it was created probably has a stale price on it, and a stale price is worse than no price.
Paid placement, stated plainly
Two of the three listing tiers cost money. Featured pins a company above the earned ordering on its city and category pages; Verified buys a human review of an insurance certificate. Both are labelled everywhere they appear, and neither is included in the score you see on any profile.
The separation is worth being concrete about, because “our algorithm is independent” is a claim every directory makes. In this codebase the earned score is computed by computeQualityScore and persisted to the listing. The paid boost is computed by a separate function, rankBoostFor, and applied only while sorting. There is no code path that writes a paid boost into a stored score.
Questions
- Does paying change my score?
- No. The score is computed from earned signals only, and the paid placement boost is applied at sort time and never written into the score. That is a structural separation in the code, not a policy we are asking you to trust: quality_score and rankBoost are different values in different places.
- What does paying actually buy?
- Featured placement pins you above the earned ordering on your city and category pages and puts you in the home page rotation, and every one of those positions is labelled Featured wherever it appears. The Verified tier buys the insurance review, not the badge — if the certificate does not check out, you do not get the badge and we refund you.
- Can I pay to remove a bad review?
- No, and there is no price at which that changes. You can respond publicly to any review on your listing once you have claimed it, which is a considerably better outcome for you than deletion anyway.
- The default sort is Recommended. Is that just ads?
- Recommended is the only sort that honours paid placement. Every other sort on the site — highest rated, lowest published price, recently added, name — is a pure ordering of the same data with no paid influence at all. If you do not want to see paid placement, change the sort.
- Why is a company with 4.9 stars below one with 4.5?
- Almost always because reviews are only 15 of the 100 points, and the lower-rated company published its pricing, sent us an insurance certificate, or has more certified technicians. Open both profiles and the score breakdown in the sidebar will show you exactly which components differ.
Think a score is wrong? Open the profile — the sidebar breaks the number down by component. If it still looks wrong, tell us.