Introduction and Background
The Turkish Competition Board (“Board”) issued an important commitment decision[1] (“Decision”) concerning Sahibinden Bilgi Teknolojileri Pazarlama ve Ticaret Anonim Şirketi ("Sahibinden"), one of Türkiye's leading online listing platforms. Sahibinden operates the website sahibinden.com, which brings together buyers and sellers across a broad range of listing categories, including real estate and second-hand vehicles.
The Board issued the Decision within the scope of an investigation (“Investigation”) initiated to determine whether Sahibinden had abused its dominant position in breach of Article 6 of Law No. 4054 on the Protection of Competition. The Decision is particularly relevant for the Board’s assessment of leveraging, data usage, and advertising practices in digital platform ecosystems.
In its previous decisions, the Board had found that Sahibinden holds a dominant position in the markets for (i) "online platform services for corporate members' vehicle sales (B2B)" and (ii) "online platform services for individual members' vehicle sales (C2C)". Against this background, the Board investigated whether Sahibinden had abused its dominant position in these markets by leveraging it to support its "Otobid" business line. Otobid enables individual vehicle owners to sell their vehicles to corporate buyers through an online auction model.
The Board initiated the Investigation following complaints alleging, in essence, that Sahibinden used the advantages stemming from its strong position in online vehicle listing services to support Otobid in the adjacent market for online second-hand vehicle purchase and sale services. In particular, the complaints and the Board’s assessment raised concerns that Sahibinden’s large user base, traffic advantage, listing data, strong brand recognition, and high platform visibility could provide Otobid with significant competitive advantages over rivals lacking access to comparable advantages, thereby creating entry barriers and potentially leading to market foreclosure in the relevant adjacent market.
During the Investigation, the Board imposed interim measures on Sahibinden, including obligations (i) not to display Otobid on the Sahibinden homepage in a manner overriding the vehicle listing option, (ii) to prevent the redirection of individual users to Otobid services during the listing process, and (iii) to take all necessary organizational, operational, administrative and technical measures to prevent the use of user and listing data obtained through both the corporate members' and individual members' vehicle sales platform services in the online second-hand vehicle purchase and sale services market.
1. Competitive Concerns and the Board’s Assessment
The Board’s concerns focused primarily on two areas: data-related concerns and advertising-related concerns. In this context, the Decision refers to the concept of leveraging, namely the use of market power held in one market to strengthen a position or restrict competition in a related market. The Board assessed whether the use of data obtained through Sahibinden’s listing services could confer an exclusionary advantage on Otobid in the market for online second-hand vehicle purchase and sale services.
With respect to data-related concerns, the Board noted that Sahibinden users entering vehicle listing information could be redirected to Otobid before completing the listing process and before the relevant vehicle information became public. The Board considered that, in this process, information obtained by Sahibinden through its online listing services was used within Otobid. It further observed that user agreements, consent texts, and notifications indicated the existence of data transfers and data flows between Sahibinden’s listing, auction, and inspection services. The Board therefore assessed that such data usage practices could strengthen Otobid’s competitive position and create entry barriers for rival undertakings.
In addition to data-related concerns, the Decision also addresses advertising-related concerns. The Board examined whether Sahibinden’s extensive advertising expenditure — both on-platform and off-platform — together with its on-platform promotions and redirections for Otobid, could restrict competition. In this regard, the Board noted that Otobid-related advertisements, promotional displays, and notifications appeared in various sections of the Sahibinden platform, including the homepage, vehicle-category search results pages, and vehicle listing detail page. The Board considered that these practices, together with Sahibinden’s financial strength and its ability to reach users through its own online listing platform, could confer an undue competitive advantage on Otobid and result in potential exclusionary effects.
Certain allegations raised in the complaints — including bundling/tying between Sahibinden’s listing services and Otobid, as well as alleged exploitative effects — were excluded from the scope of the Investigation at the outset, as the Board found insufficient grounds to proceed with an investigation on those specific matters.
2. Initial Commitment Proposal and the Board’s Assessment
Sahibinden submitted an initial package of several commitments to address the identified concerns, which included: (i) the removal of Otobid-related displays, advertisements, banners, links, tabs, and similar elements from Sahibinden’s website and mobile application; (ii) the prevention of redirections to Otobid during the vehicle listing process; (iii) the prevention of the use of non-public data obtained through vehicle listing activities for Otobid through organizational, operational, administrative, and technical measures; and (iv) the introduction of a cap on Otobid’s advertising expenditure. The third commitment, in particular, encompassed measures such as the separation of websites and applications, the establishment of separate data teams and databases, restrictions on Otobid’s access to non-public vehicle listing data, limitations on Sahibinden’s use of data obtained through Otobid for its other services, logging and record-keeping obligations, organizational separation measures, and revisions to data use policies and user agreements.
The Board found that the commitments addressing data-related concerns were, in principle, capable of resolving the relevant competition concerns. In reaching this view, the Board took into account that these commitments were already being implemented pursuant to the interim measures and that they ensured a comprehensive separation between Sahibinden’s online vehicle listing services and Otobid/S-ATS service through website and application separation, separate data teams and databases, restrictions on data access and cross-use, organizational and operational separation measures, logging and record-keeping mechanisms, and revisions to data use policies and user agreements. However, the Board concluded that the initial commitment package, viewed as a whole, did not satisfy the conditions set out in Communiqué No. 2021/2, namely proportionality, suitability to address the competition concerns, timely implementation, and effective enforceability.
In particular, the Board considered that the fourth commitment — introducing a cap on advertising expenditure calculated by reference to “total transaction value” — was neither suitable nor proportionate to address the advertising-related concerns. The Board noted that advertising restrictions triggered only upon exceeding certain market share or sales volume thresholds would come into effect only after the relevant anticompetitive effects had already materialized. The Board also considered the market share threshold to be ambiguous and the overall design not suitable to address the concern or effectively enforceable.
Accordingly, the Board rejected the initial commitment package and granted Sahibinden a one-off opportunity to revise the rejected commitments within ten days.
3. Revised Commitments and the Board’s Assessment
In its revised submission, Sahibinden maintained the first three commitments and revised only the fourth commitment relating to advertising expenditure. The Board assessed the revised structure as more realistic and better tailored to address the advertising-related concerns.
Under the revised commitment, if a specified Otobid vehicle sales volume threshold is exceeded within a fiscal year, Otobid’s revenues from second-hand vehicle purchase and sale activities must cover the relevant variable costs and advertising expenditures. This mechanism is intended to alleviate concerns that Sahibinden could cross-subsidize Otobid’s advertising and operational activities by relying on financial strength derived from its position in the online listing services market.
The Board found the revised commitment to be proportionate and suitable to address the competition concerns identified in the Investigation. It also viewed positively the revised termination mechanism, under which the commitments would remain subject to the Board’s approval prior to their being lifted, thereby allowing the Board to maintain the commitments if effective competition has not yet been restored.
Ultimately, the Board found that the revised commitments, assessed as a whole, were proportionate to the competition concerns, suitable to address those concerns, capable of being implemented in a short time frame, and effectively enforceable. The Board therefore rendered the final commitments binding and terminated the Investigation without a finding of infringement.
Conclusion
This Decision represents a significant example of the Board's intensified scrutiny of digital platform ecosystems, particularly where a platform holding a strong position in one market expands — or is suspected of expanding — into an adjacent market by relying on data access, user traffic, brand visibility, and advertising scale.
The Decision confirms the Board's willingness to resolve complex digital-platform investigations through binding commitments, provided that the commitment package, taken as a whole, is proportionate, suitable to address the identified competition concerns, capable of swift implementation, and effectively enforceable and monitorable.
For undertakings operating in multi-sided platform ecosystems, particularly those offering or acquiring vertically adjacent services, the Decision serves as a reminder that data flows between platform segments, on-platform promotion of integrated services, and the use of a dominant platform's financial strength to support operations in adjacent markets may each independently attract regulatory scrutiny and may collectively form the basis for a leveraging theory of harm.
[1] The Board decision dated 25 December 2025 and numbered 25-49/1208-683.