Only one in 15 advertisers knew what their No.1 survey had asked

"Everyone else in our industry says No.1. If we don't, that counts against us."

That is how one advertiser explained its "No.1" claim to the Consumer Affairs Agency. Competitors making the claim was the most common reason advertisers gave. The quote comes from a report the agency published on 26 September 2024, after collecting No.1 claims from real advertising, surveying consumers and interviewing the companies making the claims.

Most of the advertisers had not checked whether the claim did anything for them.

What consumers read into it

The agency surveyed 1,000 consumers from 1 to 9 August 2024. Among those who had seen such claims, about half said a No.1 claim influenced their purchase decisions.

They also read a lot into it. Shown a sample ad reading "No.1 in customer satisfaction", 55.5% said the product was probably better than competing products, and 56.8% assumed the ranking came from a survey of people who had actually used it.

That assumption is where the trouble starts.

How the claims get made

The agency collected 368 samples of No.1 claims and "X% of doctors recommend" claims. Satisfaction was the most common theme among the No.1 claims, with 71 samples.

In interviews, more advertisers said they had been approached by a research or consulting firm than said they had gone looking for one. Many chose a firm on price, commonly ¥100,000 to several hundred thousand yen per phrase. Some firms pitched with lines such as "no extra charge until you get first place". Some assured clients that their lawyer had checked everything.

Some of those firms were delivering "image surveys". Respondents were shown the websites of the client and a set of competitors and asked which one seemed best on some measure, whether or not they had ever used any of them. The result was then sold as the basis for "No.1 in satisfaction".

Of the 15 advertisers interviewed, only one knew what the survey had actually asked, which competitors it had been compared with, and what the respondents had been shown. Several did not have the report on file and had to ask the research firm for it again once the agency came calling.

What the agency expects

The report sets out four conditions a survey must meet before it can support a No.1 claim based on opinion:

1. The products it is compared with are chosen properly, which means including the main products in the market and not only the top results of a web search
2. The respondents are chosen properly: at random, not only your regular customers and never your own staff, and for a satisfaction claim, people who have actually used the product
3. The survey is carried out fairly
4. The wording of the claim matches what the survey found

A footnote such as "based on a website impression survey" does not rescue a satisfaction claim, the report says. The ad still tells the reader something the survey did not measure.

This is enforced

The report cites 13 recent cases, dated June 2023 to March 2024, in which No.1 claims based on opinion were found to breach the Act against Unjustifiable Premiums and Misleading Representations. It did not end there. In the agency's FY2025 enforcement report, a frozen meal delivery service had a commitment plan approved on 19 September 2025 over three rankings, including "No.1 recommended by professional chefs", that the agency suspected were not based on objective surveys.

A better use of the space

If you have a real number, use it and say where it comes from: units sold in a stated period, the share of customers who reorder, the number of reviews from verified buyers.

If you do not, drop the claim. The report's own interviews suggest few advertisers could say what it was earning them anyway.