> For clean Markdown of any page, append .md to the page URL. > For a complete documentation index, see https://docs.pixalate.com/llms.txt. > For AI client integration (Claude Code, Cursor, etc.), connect to the MCP server at https://docs.pixalate.com/_mcp/server. # Seller Trust Index (STI) > Seller Trust Index (STI) 2.0 methodology. How sellers are ranked on Arbitraged Inventory Ratio, DIRECT Publisher Penetration and Direct Impression Volume, and how to read the supplemental IVT, MFA, delisted-app and bundle ID signals. The Seller Trust Index (STI) ranks web, mobile and connected TV (CTV) sellers, including supply-side platforms (SSPs), that are listed in ads.txt and app-ads.txt files. Sellers are ranked on how much authorized, direct inventory they control in each country, so you can spot sellers that mostly resell inventory. > **Note** > > This page describes STI 2.0, which replaced STI 1.0 on April 1, 2026. *Video (2.5 min): how the Seller Trust Index ranks sellers and how to read it.* ## What the STI measures The STI ranks sellers on the scale of their direct relationships with publishers within each country. It uses the [SupplyChain Object (SCO)](/compliance/sco) to get a multidimensional view of ad transactions. * **Rankings are relative to peers within each country.** A seller's position compares it only with other sellers in the same market. * **Rankings use only buy-side data.** * **Other traffic signals don't change the rank.** Invalid traffic (IVT), made-for-advertising (MFA) traffic and delisted-app traffic are shown next to each ranking as supplemental data. Pixalate analyzes more than 30 billion global advertising transactions a month to rank more than 300 sellers across more than 100 countries. ## Indexes and coverage There are three indexes. Each is available by quarter and by country. | Index | Inventory | Stores covered | | ---------- | --------------------------------------------- | ---------------------------------------------------------------------------------------------- | | Web STI | Web traffic, including mobile web and desktop | Not applicable | | Mobile STI | Mobile in-app traffic | Apple App Store (iOS), Google Play (Android) | | CTV STI | Connected TV traffic | Roku Channel Store, Samsung Smart TV, Amazon Fire TV, Apple TV tvOS App Store, LG TV App Store | The public rankings are on the [Seller Trust Index page on pixalate.com](https://www.pixalate.com/rankings/?group=app\&reportId=sellerTrustIndex). ## How sellers are ranked Sellers are ranked only on a composite index that measures the scale and authorization of their direct inventory relationships in each country. The ranking model looks at: * **What sellers claim:** how many publishers that sell ads list the seller as DIRECT in their ads.txt or app-ads.txt file, as detected by Pixalate. * **Verification of seller claims:** the scale and ratio of the seller's impressions that actually flowed through an authorized direct path, according to Pixalate's SCO analysis. * **Seller arbitrage risk:** Pixalate's independent risk rating for selling more than 50% of inventory as a reseller, according to Pixalate's SCO analysis. ### Final rank The final rank is a composite score of how much authorized, direct inventory a seller controls in a country. It combines three components: | Component | Definition | | ---------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | Arbitraged Inventory Ratio | The share of a seller's total measured impressions in the country that aren't transacted as authorized direct (non-reseller) inventory. Direct status comes from the seller's presence as a DIRECT entry in publishers' ads.txt or app-ads.txt files. | | Direct Impression Volume | The seller's absolute count of direct impressions in the country during the quarter, percentile-ranked against all other eligible sellers in the same country. | | DIRECT Publisher Penetration | The number of publishers in the country that generate advertising impressions and list the seller as a DIRECT authorized seller in their ads.txt or app-ads.txt file. Measured per domain for web and per app for mobile and CTV, and percentile-ranked within the country. | ## Supplemental signals These signals are reported next to each seller's rank as context for buyers. They don't affect the rank, and which ones you see depends on the platform. | Signal | Shown for | Definition | | ------------------------------------------------------------------------------------ | ---------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | General Invalid Traffic (GIVT) Ratio | Web, mobile, CTV | The share of the seller's impressions designated as GIVT by Pixalate's MRC-accredited IVT detection methods. | | Sophisticated Invalid Traffic (SIVT) Ratio | Web, mobile, CTV | The share of the seller's impressions designated as SIVT by Pixalate's MRC-accredited IVT detection methods. | | Made for Advertising (MFA) Traffic Ratio (shown as MFA App Traffic Ratio for mobile) | Web, mobile | The rate of [MFA](/compliance/mfa-methodology) traffic associated with the seller, as a percentage of total impressions, as measured by Pixalate. | | Delisted App Traffic Ratio | Mobile | The seller's traffic on apps delisted from the Apple App Store and Google Play, plus fraudulent, malformed or unidentified mobile bundle IDs, as a percentage of total impressions. | | Fraudulent Bundle ID Traffic Ratio | CTV | The percentage of the seller's traffic that uses fraudulent, malformed or unidentifiable bundle IDs in the bid stream instead of standardized CTV app store IDs. | For the IVT types Pixalate reports, see [IVT Taxonomy 2.0](/trust/ivt-taxonomy). ## Read the rankings table The rankings table in the MRT shows **Rank**, **Seller Name**, **Risks** (badges such as **High SIVT** and **High GIVT**), **Arbitraged Inventory Ratio**, **'DIRECT' Publisher Penetration**, and the supplemental signals for the platform, such as **SIVT Ratio**, **GIVT Ratio**, **Delisted App Traffic Ratio** and **MFA App Traffic Ratio** for mobile. CTV rankings have a platform toggle (Roku, Fire TV, Samsung, tvOS and LG TV) and a **Fraudulent Bundle ID Traffic Ratio** column. Direct Impression Volume is part of the rank but isn't shown as a column. Select a seller's name to open its [Seller Insights](/mrt/seller-insights) page. ## Interpret the rankings ![Seller Trust Index 2.0 rankings table](/_fern-img/44010d776f6716f814cbd1859c7b2614da607616e203f57c82b4caeb2bc559b6.webp) ### Final rank A seller's rank reflects the strength and depth of its direct supply presence in a specific country. A higher rank mainly means the seller: * Transacts most of its impressions in the country as direct, non-reseller inventory. * Has a meaningful volume of direct impressions compared with other sellers in that market. * Holds direct authorization relationships with many local publishers. A lower rank doesn't mean the supply isn't legitimate. Lower-ranked sellers rely more on reseller paths, are authorized by fewer local publishers, or operate at a smaller scale in the country. If you want fewer supply chain hops and direct access to local inventory, favor sellers with higher ranks in the country you buy in. Review the supplemental signals separately from the rank. ### GIVT and SIVT ratios IVT can show up as proxy usage, app spoofing and high-risk devices. Lower IVT gives buyers more confidence that fraud has been mitigated. * **GIVT** is deterministic. Examples include data center IPs, bot activity and duplicate impressions. * **SIVT** can include display impression fraud, app spoofing and high-risk devices. ### MFA Traffic Ratio MFA is a risk for both sides of the market. For sellers, it can undermine inventory quality and damage their reputation. For buyers, ads on cluttered MFA sites can make campaigns less effective. See [Made for Advertising (MFA)](/compliance/mfa). ### Delisted App Traffic Ratio This ratio shows how much of a seller's traffic runs on delisted apps. Apps are delisted for many reasons: publisher-level fraud, malware, adware, backdoors exploited through bad SDKs, or the developer removing the app. Apps can also be delisted for copyright or policy violations that have nothing to do with fraud. A higher ratio means the seller is more likely to be transacting on riskier apps that aren't listed in an established app store. See [Delisted apps (DEFASE)](/data-feeds/defase). ### Fraudulent Bundle ID Traffic Ratio Standardized app store IDs reduce fragmentation in CTV and align buyers and sellers on the same inventory format, so buyers can be more confident about what inventory they're getting. See [CTV bundle IDs](/mrt/ctv-bundle-ids) and [Malformed CTV bundle IDs](/data-feeds/malformed-ctv-bundle-ids). ## Related * [Publisher Trust Index (PTI)](/mrt/publisher-trust-index) * [Seller Insights](/mrt/seller-insights) * [SCO validation and verification](/compliance/sco) * [Supply path optimization (SPO) data feed](/data-feeds/spo)