Unlock More
Dynamic Delivery
with Ever-Evolving DOOH

MASTRUM, jeki’s digital OOH marketplace,
integrates global cutting-edge technology
with deep insights rooted in Japanese
business practices and local expertise in
“capturing mobile audiences and enabling
optimal communication.” By doing so, this
fusion allows MASTRUM to address the
challenges faced by both advertisers and
media owners, offering innovative solutions
that drive results.

Do any of these issues
sound familiar?

    • Issue 1

      “I want to schedule ad deliveries
      flexibly, tailored to content and
      optimal time slots.”

      MASTRUM supports a wide range of ad delivery formats, enabling flexible distribution tailored to each advertiser’s products and services.
      * Some services are currently under development.

    • Issue 2

      “It is often challenging
      to measure the effectiveness
      of OOH campaigns.”

      With MASTRUM’s proprietary measurementexpertise, we provide in-depth postcampaign reports to support your future performance evaluations.

    Learn more about
    our services

    • Issue 1

      “I want to expand my media sales channel.”

      MASTRUM-SSP leverages our extensive sales network built over the years to enable integration with various DSPs, allowing media owners to attract ad placements from advertisers they previously couldn’t reach.

      Additionally, media owners can control their distribution channels on a per-owner basis, ensuring secure and manageable sales operations.

    • Issue 2

      “I want to provide media value that meets clients’ needs.”

      MASTRUM addresses traditional challenges in OOH by enabling targeted ad delivery and other advanced capabilities, allowing us to offer media at pricing that aligns with advertisers’ specific needs.
      * Some services are currently under development. ​

    Learn more about our services

We offer unique solutions by combining
the expertise and technology developed by JR East Marketing
& Communications (jeki)

SERVICE
3 Key Approaches MASTRUM Delivers Value

  1. POINT01

    Data-based Audience measurement and performance evaluation

    By extracting data from beacons and other sources, MASTRUM enables measurement of audience metrics – such as reach and demographic attributesacross a wide range of OOH media.

    This data-driven approach addresses one of OOH’s long-standing challenges:performance verification. It empowers advertisers to make more informed, effective media placements.

  2. POINT02

    From digital to traditional media: high-level transactions enabled by a wide range of premium ad inventory

    With extensive access to premium ad spaces – from digital screens to traditional formats – MASTRUM enables seamless, high-value transactions.

    Our inventory includes exclusive placements such as in-station and in-train digital media,offering advertisers unique opportunities across diverse touchpoints.

  3. POINT03

    Optimized exposure at the right time, based on diverse external data sources

    By expanding our network of data-providing partners, MASTRUM enables advanced targeting through the integration of multiple data sources.

    This approach enhances the precision of targeting, allowing advertisers to reach the right people, in the right place, at the right time – with maximum impact.

VISION
MASTRUM’s vision

JR East Japan Marketing &Communications has built a DSP/SSP systemenabling transactions across all OOH media.This platform service is designed tomaximize effectiveness and revenue throughdata-driven programmatic transactions.Looking ahead, we plan to expand beyondJR East’s media, extending to other railway networks, urban signage, and integrating with online and virtual spaces to create a seamless, networked advertising ecosystem.
Note: DSP (Demand Side Platform) allows advertisers to place ads, while SSP (SupplySide Platform) facilitates ad sales to publishers.