Pixalate’s Web STI 2.0 rates sellers by arbitrage risk and invalid traffic (ad fraud) risk across 100+ markets, including USA, Canada, UK, Germany, France, Japan, Singapore, China, and Brazil; Index Exchange, Google Ad Exchange, Seedtag among leaders
LONDON, June 8, 2026 — Pixalate, an ad fraud and privacy compliance platform, today released the Q1 2026 Web Seller Trust Index (STI) 2.0 rankings. STI 2.0 ranks open programmatic sellers across 100+ markets and fully differentiates between arbitraged vs. authorized publisher-direct inventory. The index is free, public, and updated quarterly.
For each seller in each country, the model measures:
In global web traffic, 20.8% of authorized inventory was resold rather than sold publisher-direct in Q1 2026 — the highest of any channel (above mobile's 16.2% and CTV's 4.1%, per Pixalate's Q1 2026 Mobile and CTV Seller Trust Indexes). The average SSP arbitrage rate edged up marginally (about 0.1 percentage points) quarter-over-quarter.
At the country level, the share of ranked SSPs that are primarily arbitrageurs rose most in Spain (+15 pp), Italy (+12 pp) and Canada (+11 pp), and fell most in Japan (−18 pp) and Turkey (−7 pp).
The following tables show the top-ranked sellers in select countries based on Web Seller Trust Index scores for Q1 2026. Full rankings for 100+ countries are available at pixalate.com.
|
Rank |
Seller |
Risks |
Arbitraged Inventory Ratio |
‘DIRECT’ Publisher Penetration |
SIVT Ratio |
GIVT Ratio |
MFA Traffic Ratio |
|---|---|---|---|---|---|---|---|
|
1 |
Index Exchange |
0% |
34,303 |
8% |
1% |
< 1% |
|
|
2 |
Onetag |
High GIVT |
1% |
35,071 |
10% |
3% |
12% |
|
3 |
Seedtag |
High GIVT |
< 1% |
25,606 |
7% |
2% |
16% |
|
4 |
GumGum |
High GIVT |
< 1% |
25,733 |
6% |
3% |
< 1% |
|
5 |
AdaptMX |
High GIVT |
1% |
33,146 |
9% |
19% |
11% |
|
Rank |
Seller |
Risks |
Arbitraged Inventory Ratio |
‘DIRECT’ Publisher Penetration |
SIVT Ratio |
GIVT Ratio |
MFA Traffic Ratio |
|---|---|---|---|---|---|---|---|
|
1 |
Seedtag |
High SIVT |
< 1% |
12,738 |
23% |
6% |
4% |
|
2 |
Google AdExchange |
11% |
17,546 |
11% |
< 1% |
8% |
|
|
3 |
Blockthrough |
High SIVT |
0% |
10,045 |
13% |
< 1% |
1% |
|
4 |
CafeMedia |
0% |
4,074 |
6% |
< 1% |
11% |
|
|
5 |
Media.Net |
High GIVT |
6% |
15,884 |
13% |
5% |
14% |
|
Rank |
Seller |
Risks |
Arbitraged Inventory Ratio |
‘DIRECT’ Publisher Penetration |
SIVT Ratio |
GIVT Ratio |
MFA Traffic Ratio |
|---|---|---|---|---|---|---|---|
|
1 |
Google AdExchange |
9% |
11,586 |
2% |
< 1% |
30% |
|
|
2 |
Seedtag |
High GIVT |
< 1% |
8,197 |
3% |
2% |
35% |
|
3 |
The Ozone Project |
0% |
4,871 |
3% |
< 1% |
42% |
|
|
4 |
AdaptMX |
High GIVT |
3% |
9,677 |
7% |
1% |
26% |
|
5 |
Index Exchange |
5% |
9,750 |
7% |
< 1% |
2% |
|
Rank |
Seller |
Risks |
Arbitraged Inventory Ratio |
‘DIRECT’ Publisher Penetration |
SIVT Ratio |
GIVT Ratio |
MFA Traffic Ratio |
|---|---|---|---|---|---|---|---|
|
1 |
Media.Net |
2% |
6,956 |
2% |
< 1% |
2% |
|
|
2 |
Google AdExchange |
13% |
8,584 |
2% |
< 1% |
3% |
|
|
3 |
AdaptMX |
2% |
6,438 |
12% |
< 1% |
44% |
|
|
4 |
Verve |
3% |
4,914 |
6% |
< 1% |
1% |
|
|
5 |
OMS |
0% |
2,087 |
9% |
< 1% |
5% |
|
Rank |
Seller |
Risks |
Arbitraged Inventory Ratio |
‘DIRECT’ Publisher Penetration |
SIVT Ratio |
GIVT Ratio |
MFA Traffic Ratio |
|---|---|---|---|---|---|---|---|
|
1 |
Google AdExchange |
High GIVT |
< 1% |
4,648 |
9% |
4% |
15% |
|
2 |
Media.Net |
< 1% |
3,718 |
11% |
< 1% |
< 1% |
|
|
3 |
Criteo Commerce Grid |
11% |
4,231 |
10% |
< 1% |
< 1% |
|
|
4 |
Amazon Publisher Services |
7% |
4,206 |
4% |
< 1% |
7% |
|
|
5 |
AdaptMX |
< 1% |
3,434 |
9% |
< 1% |
6% |
The following metrics are disclosed for each seller in each country:
|
Metric |
Description |
|---|---|
|
Arbitraged Inventory Ratio |
The percentage of a seller’s measured impressions that did not flow through an authorized-direct path — i.e., the share sold as a reseller or arbitrage intermediary, per Pixalate’s SCO analysis. |
|
‘DIRECT’ Publisher Penetration |
The number of websites with open programmatic ad activity, as measured by Pixalate, in a country that lists the seller as a DIRECT partner in their ads.txt file — a measure of potential direct access in a given market. |
|
SIVT Ratio |
Sophisticated Invalid Traffic as a percentage of total impressions, per Pixalate’s MRC-accredited detection. |
|
GIVT Ratio |
General Invalid Traffic as a percentage of total impressions. Includes known bots, spiders, and other non-human traffic identified through industry-standard filtration lists. |
|
MFA Traffic Ratio |
The percentage of a seller’s ads sold on websites that are flagged as likely Made-For-Advertising (MFA), according to Pixalate. |
Seller overall rankings are a composite score based on Arbitraged Inventory Ratio, DIRECT Publisher Penetration, and Authorized-Direct Volume.
The following table shows the share of web SSPs operating in each country that are primarily resellers — meaning over half of their measured impressions were not delivered through an authorized-direct path, as assessed by Pixalate.
|
Country |
# of SSPs Ranked on Web STI |
# of SSPs Ranked With >50% Arbitraged Inventory Ratio |
% of SSPs Ranked With >50% Arbitraged Inventory Ratio |
|---|---|---|---|
|
Turkey |
14 |
7 |
50% |
|
Italy |
35 |
11 |
31% |
|
France |
46 |
14 |
30% |
|
Spain |
23 |
7 |
30% |
|
Germany |
84 |
20 |
24% |
|
Japan |
32 |
7 |
22% |
|
Canada |
65 |
14 |
22% |
|
Mexico |
48 |
10 |
21% |
|
United States |
148 |
22 |
15% |
|
United Kingdom |
62 |
6 |
10% |
The Pixalate Seller Trust Index ratings are free and open to the public. See the full Q1 2026 Web Seller Trust Index ratings at pixalate.com.
Pixalate also publishes the Mobile Seller Trust Index and CTV Seller Trust Index.
About Pixalate
Pixalate is a global platform specializing in privacy compliance, ad fraud prevention, and digital ad supply chain data intelligence. Founded in 2012 and recognized by UNICEF as a “key innovator” for children’s online privacy, Pixalate is trusted by regulators, data researchers, advertisers, publishers, ad tech platforms, and financial analysts across the Connected TV (CTV), mobile app, and website ecosystems. Pixalate is accredited by the MRC for the detection and filtration of Sophisticated Invalid Traffic (SIVT). pixalate.com
Disclaimer
The content of this press release, and the Seller Trust Indexes (collectively, the “Indexes”), reflect Pixalate’s opinions with respect to factors that Pixalate believes may be useful to the digital media industry. As cited in the Indexes, the ratings and rankings in the Indexes are based on a number of metrics and Pixalate’s opinions regarding the relative performance of each seller with respect to the metrics. The data is derived from buy-side, predominantly open auction, programmatic advertising transactions, as measured by Pixalate. Any references to outside sources in the Indexes and herein should not be construed as endorsements. Pixalate’s opinions are just that, opinions, which means that they are neither facts nor guarantees; and neither this press release nor the Indexes are intended to impugn the standing or reputation of any person, entity or website.
IVT rates and scores derived from each vendor’s own proprietary methods and independent analysis may depict differing results and opinions across measurement providers. Any party’s reliance on Pixalate’s Indexes, rankings, IVT opinions, or related data is entirely at that party’s own risk. Pixalate makes no guarantees, representations, or warranties — express or implied — regarding the accuracy, completeness, or applicability of its opinions or data to any particular purpose or circumstance.
Per the MRC, “‘Fraud’ is not intended to represent fraud as defined in various laws, statutes and ordinances or as conventionally used in U.S. Court or other legal proceedings, but rather a custom definition strictly for advertising measurement purposes. Also per the MRC, “‘Invalid Traffic’ is defined generally as traffic that does not meet certain ad serving quality or completeness criteria, or otherwise does not represent legitimate ad traffic that should be included in measurement counts. Among the reasons why ad traffic may be deemed invalid is it is a result of non-human traffic (spiders, bots, etc.), or activity designed to produce fraudulent traffic.”