Intellectual Property in Daily Life: An Introduction to 'Effectuation x IP' You Can't Afford to Miss: How Mercari Conquered the Flea Market App Market
Do you have concerns like these? 'I want to launch a new business in an uncertain market, but I don't know how much risk I should take to test it,' or 'I have an idea, but I can't visualize how to incorporate patents and trademarks into my strategy.' This article, which uses the Mercari 'flea market app' as a case study, is for you. The flea market app market was a world with many existing services and competitors. In this environment, the approach Mercari took—interpreted through the lens of 'effectuation'—was to repeat experiments within the scope of affordable loss and firmly protect the results with patents and trademarks. This is a realistic story that could happen tomorrow for those in charge of new businesses or those considering restructuring after a business succession.
What is Effectuation? The Difference from Causation
Effectuation is a 'principle of entrepreneurial decision-making' composed of five principles: 'Bird-in-Hand' (starting from one's own experience, knowledge, and network), 'Affordable Loss' (betting only what you can afford to lose), 'Crazy Quilt' (co-creating the business with partners you can involve), 'Lemonade' (turning the unexpected into an opportunity), and 'Pilot' (steering the future through your own actions rather than prediction).
On the other hand, Causation is a 'business plan' approach that involves precisely predicting goals or market size and working backward to accumulate the necessary resources and plans. Effectuation is considered to be a better fit for markets with high uncertainty. If you would like to learn more about effectuation, please refer to this Note article as well.
→ https://note.com/muesli14/n/n62a5eedc8d31
Overview of the Mercari 'Flea Market App' and Its Relationship with the Five Principles of Effectuation
Mercari launched its C2C flea market app service on July 2, 2013 [1], grew into one of the largest flea market apps in Japan in just five years, and was listed on the Tokyo Stock Exchange Mothers market on June 19, 2018 [2]. Despite the presence of competitors like Fril (now Rakuma) in the market, it expanded rapidly through a 'UX that allows anyone to list items easily' and marketing centered on TV commercials, establishing an overwhelming share of the C2C flea market.
This process overlaps with the five principles of effectuation. Founder Shintaro Yamada is a serial entrepreneur with a track record including launching auctions at Rakuten and founding and selling Unoh [3]. The fact that he launched the service starting from his 'Bird-in-Hand' (his own experience, network, and capital) is a classic example of the 'Bird-in-Hand' principle. Starting with 20 million yen in initial capital, he conducted market validation while keeping fees low, and the decision to proceed with advertising investment and feature development under the premise of 'this is the range I can afford to lose' corresponds to the 'Affordable Loss' principle. The move to involve former Mixi CFO Tomoaki Koizumi and numerous VCs and business partners in December 2013 [4] to increase capital and human resources is a stakeholder strategy in line with the 'Crazy Quilt' principle. The series of services that were tested and then withdrawn, such as Mercari Atte (ended May 31, 2018) and Mercari Channel (ended July 8, 2019), can be seen as the practice of 'Lemonade' and 'Pilot,' where failures are used as learning resources while refining the value of the main flea market app.
Utilized Intellectual Property and IP Strategy in Effectuation
Mercari has built an IP portfolio that combines three technical patents related to the core UX of the flea market app and three trademarks protecting the 'Mercari' brand [5]. Technical patents include Patent 6315636 (listing support technology/expired), Patent 6589038 (product information display technology linked with wearable devices/active), and Patent 7225312 (simple listing via barcode reading/recommended price setting technology/active). Regarding trademarks, three have been registered: Registration No. 5599645, Trademark Registration No. 5739824, and Trademark Registration No. 5981250, covering a range that gradually expands from application software to marketplace operation and payment/financial services [5][6].
From the perspective of effectuation, these IP assets are tied to multiple principles. In relation to the 'Affordable Loss' principle, patents protecting the core of the UX reduce the risk that the results of UI/UX improvements and advertising investments made with limited funds will be copied by competitors [5][6]. When repeating experiments in an uncertain market, if the results are immediately imitated, the design of the affordable loss collapses. By drawing a line with patents to say 'this is our home turf,' it becomes easier to secure the returns of experimental results for the company.
In relation to the 'Pilot' principle, it is important that a system is in place where engineers and product development teams collaborate with the IP department to actively patent inventions born during the process of UX improvement [6][7]. In relation to the 'Crazy Quilt' principle, Mercari pursues an IP strategy called 'Open & Defensive,' where it protects its core technologies with patents while opening up some technologies to expand the ecosystem, and at the same time, promotes collaboration to defend against patent offensives from other companies [7].
Differentiation Between Patents and Trademarks
In Mercari's IP strategy, there is a clear division of roles between patents and trademarks. Patents are for protecting 'UX/system differentiation points,' with a focus on rights for technologies behind the experience that makes users feel 'Mercari is easy to use and convenient,' such as listing support, barcode listing, and wearable device integration [5][6]. This makes it difficult to imitate not only the look of the UI but also the operation flow and the underlying logic, maintaining its advantage as a platform.
On the other hand, trademarks play a role in protecting 'brand trust' and 'business scalability.' Since the risk of fakes and trouble always exists in the C2C flea market, the image of safety and security tied to the name 'Mercari' is the lifeblood of the business [6][7]. The fact that they secured trademarks related to application software in the early stages and then gradually expanded the scope of protection in line with business expansion, such as marketplace operation and payment/finance, is designed so that 'the brand will be consistently protected no matter how far the business expands in the future' [5].
In terms of effectuation, patents are a mechanism to 'turn differentiation elements born from experiments into insurance and weapons,' and trademarks are a mechanism to protect a 'common banner under which stakeholders can participate with peace of mind' [6][7]. To continue trial and error in an uncertain market, it is important that users and partners feel 'this brand is safe,' and trademarks underpin that psychological safety. At the same time, by securing UX superiority with patents, they have created a structure where the cycle of effectuation experiments and learning is less likely to be interrupted by competitor copying [5][6].
Summary
The success of Mercari's flea market app can be explained not only by 'good ideas' or 'financial power' but by a combination of decision-making based on effectuation and the IP strategy that supports it. Starting from available experience, networks, and capital, they determined affordable losses and repeated experiments. In the process, they protected the UX and technology born from that with patents, protected the brand with trademarks, and involved partners to turn market uncertainty into an ally.
[References]
[1] https://about.mercari.com/press/news/articles/20180702_mercarinumbers/
[2] https://about.mercari.com/press/news/articles/2018069_ipo/
[3] https://about.mercari.com/about/leadership/
[4] https://www.value-press.com/pressrelease/119676
[5] https://www.patentamuse.com/familiar-ipcase/mercari-1/
[6] https://ipdesign.blog/2025/05/15/デジタルプラットフォームの知財/
[7] https://ascii.jp/elem/000/004/017/4017718/
[8] https://www.techno-producer.com/ai-report/mercari_ip_strategy_report/
