Ad Fraud Damage Expanding Behind AI-Optimized Ad Operations, Estimated Domestic Damage in 2025 to be Approximately 159.2 Billion Yen
Spider Labs' "Ad Fraud Investigation Report (Full Year 2026)" reveals that estimated ad fraud damage in Japan reached approximately 159.2 billion yen in 2025, an increase driven by the expanding ad market. The report highlights new risks emerging from the rapid growth of AI-optimized campaigns, which exhibit higher fraud rates, and the alarming surge in "MFA sites" that exploit these automated systems, leading to significant ad spend leakage.
📋 Article Processing Timeline
- 📰 Published: April 2, 2026 at 19:00
- 🔍 Collected: April 2, 2026 at 14:30
- 🤖 AI Analyzed: April 17, 2026 at 07:17 (352h 46m after Collected)
Spider Labs Inc. (Minato-ku, Tokyo; Representative Director: Satoko Otsuki; hereinafter "Spider Labs") has announced the "Ad Fraud Investigation Report (Full Year 2026)," which summarizes the reality of ad fraud in Japan from January 1 to December 31, 2025. This report is based on annual analysis data from the ad fraud countermeasure tool "Spider AF" provided by the company, detailing the scale of ad fraud damage, its impact, and new risks in AI-optimized ad operations.
What is Ad Fraud?
The act of generating worthless impressions, clicks, or conversions through fraudulent programs, malicious users, or inappropriate sites, thereby unfairly consuming advertising costs. This includes not only malicious revenue theft but also invalid impressions, clicks, and conversions that provide no advertising effect against the advertiser's intentions.
Investigation Summary
Estimated domestic damage amounts to approximately 159.2 billion yen; losses remain high with the expansion of the ad market
In 2025, the estimated ad fraud damage in Japan was approximately 159,177,330,000 yen, an increase of 8.2 billion yen compared to the previous year. While the average occurrence rate slightly decreased, the total damage continues to trend upwards with the expansion of the overall ad market.
AI optimization menus are rapidly expanding; ad operations are moving towards "AI-first."
This year's report addresses the rapid expansion of AI optimization menus in ad operations. Delivery volume has grown by 192% in just over a year and is expected to see a continued rise in its proportion of programmatic advertising. On the other hand, AI optimization campaigns on major ad platforms show a fraud rate of up to 5.2%, more than double the overall platform average of 2.2-2.5%, highlighting new risks accompanying the advancement of automation.
Placements on MFA sites are surging; a serious risk of ad spend leakage in the AI era.
This year's report also focuses on the rapid increase in "MFA sites" (Made For Advertising), whose primary purpose is to earn advertising revenue. Spider AF detected a 1,409% year-on-year increase in placements on MFA sites and a 533% year-on-year increase in damage. These sites are rapidly expanding in number and scale, partly driven by the mass production of content using generative AI. In particular, the spread of AI optimization campaigns, whose placement control is difficult, leads to MFA sites being mistakenly recognized as "high-efficiency slots," contributing to the expansion of damage.
The investigation report also details the following:
• Trends and breakdown of ad fraud damage.
• Ad fraud risks by industry.
• Increased fraud risks in AI-optimized ads.
• New fraud methods including MFA sites.
• Comparison of performance differences based on click quality.
• The importance of data quality in determining ad performance.
Investigation Overview
Name: Ad Fraud Investigation Report (Full Year 2026)
Investigator: Spider Labs Inc.
Analysis Target: Ad traffic measured by "Spider AF Ad Fraud Countermeasures."
Analyzed Clicks: 6,058,522,153
Investigation Period: January 1, 2025 - December 31, 2025
Method: Proprietary database.
About Spider AF Ad Fraud Countermeasures
The ad fraud countermeasure tool "Spider AF Ad Fraud Countermeasures" (Spider AF) is a tool that detects and blocks ad fraud, which inevitably occurs in certain quantities during ad placement. Spider AF offers a free damage assessment for ad fraud, allowing anyone to easily implement ad fraud countermeasures with simple tag installation for automatic detection and blocking. Since its launch, it has been widely used by ad network operators, agencies, and advertisers.
About Spider Labs Inc.
Company Name: Spider Labs Inc.
Head Office Location: Minami-Aoyama ST Building 4F, 7-10-3 Minami-Aoyama, Minato-ku, Tokyo
Representative Director: Satoko Otsuki
Business Activities: Planning, development, and operation of the marketing security tool "Spider AF."
Providing security solutions for ad fraud, resale, fraudulent leads, affiliates, etc.
Established: April 2011
Website: https://jp.spideraf.com/
What is Ad Fraud?
The act of generating worthless impressions, clicks, or conversions through fraudulent programs, malicious users, or inappropriate sites, thereby unfairly consuming advertising costs. This includes not only malicious revenue theft but also invalid impressions, clicks, and conversions that provide no advertising effect against the advertiser's intentions.
Investigation Summary
Estimated domestic damage amounts to approximately 159.2 billion yen; losses remain high with the expansion of the ad market
In 2025, the estimated ad fraud damage in Japan was approximately 159,177,330,000 yen, an increase of 8.2 billion yen compared to the previous year. While the average occurrence rate slightly decreased, the total damage continues to trend upwards with the expansion of the overall ad market.
AI optimization menus are rapidly expanding; ad operations are moving towards "AI-first."
This year's report addresses the rapid expansion of AI optimization menus in ad operations. Delivery volume has grown by 192% in just over a year and is expected to see a continued rise in its proportion of programmatic advertising. On the other hand, AI optimization campaigns on major ad platforms show a fraud rate of up to 5.2%, more than double the overall platform average of 2.2-2.5%, highlighting new risks accompanying the advancement of automation.
Placements on MFA sites are surging; a serious risk of ad spend leakage in the AI era.
This year's report also focuses on the rapid increase in "MFA sites" (Made For Advertising), whose primary purpose is to earn advertising revenue. Spider AF detected a 1,409% year-on-year increase in placements on MFA sites and a 533% year-on-year increase in damage. These sites are rapidly expanding in number and scale, partly driven by the mass production of content using generative AI. In particular, the spread of AI optimization campaigns, whose placement control is difficult, leads to MFA sites being mistakenly recognized as "high-efficiency slots," contributing to the expansion of damage.
The investigation report also details the following:
• Trends and breakdown of ad fraud damage.
• Ad fraud risks by industry.
• Increased fraud risks in AI-optimized ads.
• New fraud methods including MFA sites.
• Comparison of performance differences based on click quality.
• The importance of data quality in determining ad performance.
Investigation Overview
Name: Ad Fraud Investigation Report (Full Year 2026)
Investigator: Spider Labs Inc.
Analysis Target: Ad traffic measured by "Spider AF Ad Fraud Countermeasures."
Analyzed Clicks: 6,058,522,153
Investigation Period: January 1, 2025 - December 31, 2025
Method: Proprietary database.
About Spider AF Ad Fraud Countermeasures
The ad fraud countermeasure tool "Spider AF Ad Fraud Countermeasures" (Spider AF) is a tool that detects and blocks ad fraud, which inevitably occurs in certain quantities during ad placement. Spider AF offers a free damage assessment for ad fraud, allowing anyone to easily implement ad fraud countermeasures with simple tag installation for automatic detection and blocking. Since its launch, it has been widely used by ad network operators, agencies, and advertisers.
About Spider Labs Inc.
Company Name: Spider Labs Inc.
Head Office Location: Minami-Aoyama ST Building 4F, 7-10-3 Minami-Aoyama, Minato-ku, Tokyo
Representative Director: Satoko Otsuki
Business Activities: Planning, development, and operation of the marketing security tool "Spider AF."
Providing security solutions for ad fraud, resale, fraudulent leads, affiliates, etc.
Established: April 2011
Website: https://jp.spideraf.com/