(Updated – March 1, 2024)

Welcome to the Mirror Digital Publisher Network. We are thrilled to work with you and to connect your audience with the world’s leading brands who are eager to reach a diverse multicultural audience. 

In order to ensure the success of our partnership, we are providing you with this set of “Mores” that spell out best practices as well as technical requirements. These may be updated from time to time and we will let you know of any updates.

Mores Quick Links
  • Sales Cooperation
  • Exclusive Partner Must-Haves
  • Banner Ad Placement Guidelines
  • Banner Ad Viewability Guidelines
  • Site Video Player Guidelines and Video Specs
  • Authorized Digital Sellers (ads.txt) – How To Update
  • Authorized Digital Sellers (ads.txt) – Files 
  • Publisher Restrictions

Sales Cooperation

  1. Implement consistent with the specifications provided by Mirror Digital (i) the Display Opportunities, (ii) ad-serving systems allowing Mirror Digital to create, serve and optimize delivery plans and (iii) other tracking and reporting tools and other ad technologies as reasonably determined by Mirror Digital.
  2. Implement or allow Mirror Digital access to implement HTML, Javascript or similar codes (each an “Ad Tag”) on the Publisher Sites in order to call and display Ads. 
  3. Provide dedicated technical operations resources to enable proper implementation of Mirror Digital’s ad tag and other Mirror Digital products and service integration.
  4. Provide Mirror Digital with administrative account access to Publisher’s ad server if necessary to enable Mirror Digital to serve Ads to Publisher Sites, forecast Inventory, reserve and book programmatic ad inventory, and monitor discrepancies.
  5. Include in one or more prominent locations on the Publisher Sites a message and link encouraging potential advertisers to contact Mirror Digital
  6. Conduct and promote a demographic survey of users of the Publisher Site via a mechanism provided by Mirror Digital, with a goal of generating at least 200 survey responses.
  7. Participate in Mirror Digital audience/network development programs (e.g. link building, integrating Mirror Digital cross promotion modules, etc.) and grant Mirror Digital the right, at no cost to Mirror Digital, to utilize up to five percent (5%) of Publisher’s unsold Display Opportunities to promote the Publisher Site, other publishers in the Mirror Digital Network and other Mirror Digital advertising related products and services.
  8. Subject to Publisher’s prior approval, participate in Custom Content opportunities for advertisers which are developed by Mirror Digital for the Publisher Site and/or other sites. In such cases, Mirror Digital will provide for Publisher’s review and acceptance a Custom Content participation agreement which outlines the Publisher’s deliverables, work schedule, payment terms, and deadlines.
  9. Provide Mirror Digital with an RSS or XML feed containing the full content of the Publisher Site to permit Mirror Digital to search for keywords in the Mirror Digital database.
  10. Publisher will execute the traffic assignment letters in the form attached as Exhibit B-1 and other documents that Mirror Digital may reasonably request from time to time in order for Mirror Digital to receive credit for Publisher Site traffic in third party measurement services (e.g., Comscore Media Metrix, Nielsen Online, etc.).

Exclusive Partner Must-Haves

  1. Partnership Prerequisites

New publisher partners must meet the following criteria:

  1. Publishers must not have an existing network partner or have legal permission/capability to work with Mirror Digital in addition to staying with their current network.  
  2. Must be diverse-owned with multicultural reach.  
  3. Must be hosted on a platform that allows for dynamic tag embeds on-site and within articles. (i.e., WordPress)
  4. Must have established Facebook and Instagram profiles. 
  5. Must have organic/direct (non-bot) pageviews onsite or 5K social media following.
  1. Create Regular Content

Partners must regularly (daily) publish original, engaging content.

  1. Articles should have a minimum 400- to 600-word count to increase engagement and allow for higher ad viewability.
  2. Sites should aim for a minimum of 2 page views per visit and 1 minute of time spent per visit (verifiable via publisher’s Google Analytics and/or Similar Web).
  1. Site Is Responsive/Code Is Current
    1. Mobile accounts for 55% of global traffic. Sites must be responsive and display properly across all platforms (desktop, tablet and mobile)
    2. CMS must allow for script tags to be embedded.
    3. MDI will make recommendations during audit/onboarding process.
  1. Implement Recommended Banner Ad Sizes And Types
    1. Site design must accommodate MDI recommended number of ad slots and ad sizes (or be redesigned at publisher’s cost to accommodate):
      1. Desktop: 970×250, 728×90, 300×250, 300×600, 160×600
      2. Mobile: 320×50, 300×250, 300×600, 160×600
    2. Ads must also be responsive. MDI will provide ad tags based on screen size and site needs. 
  1. Integrate Scripts On Website To Serve and Target Ad Slots
    1. Publisher must have access to the site theme for a developer or Mirror Digital to integrate ad scripts on the page.
  1. Optimize Ad Placement To Increase Viewability
    1. Place ads where readers are spending the most time on your site. Google Analytics has a heat map tool you can use to see how and where readers engage with your website. This is typically top center and within the body of articles. 
    2. 300×600, 160×600, and 320×50 (mobile anchor) have the highest viewability. Mirror Digital can assist with identifying placements.
  1. Increase Page Speed
    1. 50% of readers abandon sites that take longer than 3 seconds to load. Reducing the time it takes for your site to load ensures readers not only access content but generate ad impressions. 
    2. MDI will regularly review sites to monitor improvements. Suggestions include enabling caching, browser caching, compressing/optimizing images, using a CDN service. Also, recommend using CloudFlare.

Banner Ad Placement Guidelines

Ad Units & Sizes

  • JW player
  • Horizontal (Leaderboard)
    • Desktop: 970×250, 728×90
    • Mobile: 320×50, 300×250
  • Box/Skyscraper
    • Desktop: 300×250, 300×600
    • Mobile: 300×250, 300×600
  • MidArticle
    • Desktop: 728×90, 300×250
    • Mobile: 320×50, 728×90

Ad Placements

Desktop: 1 player + 4-5 ads per page (max 10 for viewability/performance), Leaderboard_1, Leaderboard_2, Box_1, FlexMid-Article_1, FlexMid-Article_2 (+ additional FlexMid-Articles as needed, possible every 4 paragraphs) 

Mobile: 1 player + 4-5 ads per page, Leaderboard_1, Leaderboard_2 (sticky footer), Box_1, FlexMid-Article_1, FlexMid-Article_2 (+ additional FlexMid-Articles as needed) 

  • Homepage
    • Header: Leaderboard_1 (preferably below menu)
    • Main Content Area or Sticky Footer: Leaderboard_2 & Flex
    • Sidebar: JW player and Box/Skyscraper (x 2)
  • Articles:
    • Header: Leaderboard_1 (preferably below menu)
    • In-article:  the JW player and/or FlexMid-Article (x1 or 2)
    • Below article: Leaderboard_2 
    • Sidebar:  Box/Skyscraper (x 2)
  • Mobile
    • Sticky Footer: Serve Leaderboard_2 as an anchor ad at bottom of page

Mobile Friendly

Ads must be responsive and serve based on device or screen size. 

Banner Ad Viewability Guidelines

Optimize Ad Unit Placements

Some ad units perform better than others, based on placement and page load time. Ads that are on the fold and just above the fold, in the first two paragraphs of text, and in visible sidebars tend to perform the best. Avoid placing ads at the bottom of pages or in areas that are likely to be obscured. 

Exclusive publisher partners can view performance by each placement within their reporting dashboard. Other publishers can pull a viewability report within their own ad manager to identify low-performing placements.

Refresh Ads

Enable ad refreshing on your site to increase overall viewable impression. For WordPress users, we recommend this Google-approved Ad Refresh Control plugin, to eliminate the need for heavy coding.

Please note, ads should only be set to refresh a minimum of every 30 seconds (or longer) and be with at least a 70% viewability threshhold. 

Enable Ad Lazy Loading

To improve ad viewability rates and enable faster page loads, we recommend that all publishers enable lazy loading. This can be achieved by adding a few lines of code to the publisher tags.

Here is the code with settings for optimal results:


          // Fetch slots within 5 viewports.

          fetchMarginPercent: 100,

          // Render slots within 2 viewports.

          renderMarginPercent: 100,

          // Double the above values on mobile, where viewports are smaller

          // and users tend to scroll faster.

          mobileScaling: 1.0


This should be added directly after the ad slot has been defined. Visit Google’s Developer site for more documentation. 

Reduce Your Bounce Rate

Use your site analytics to review your site’s bounce rate. The bounce rate measures the percentage of visitors who exit a website before engaging/reading content. High bounce rates can indicate a range of issues, including poor website design, longer page load, or questionable content quality. 

A bounce rate of anywhere between 25% to 40% is considered good, 41% to 55% is average, and 56% to 70% means you’ve got room for improvement. If the bounce rate is above 70%, it means that most site users are leaving before an before an ad even loads, which can also contribute to low viewability.

Site Video Player Guidelines and Video Specs

Player Positioning

The optimal position for video players is above the fold. All network sites typically have one video player embedded on their page in one of two starting positions:

  • In-stream Content
    • For larger real estate, sites may place the player in-stream content (i.e., within the body of the article). However, this is not always above the fold
  • Sidebar
    • For sites where the in-stream is considered too intrusive, they can run on the right rail/sidebar. This position is typically above the fold.

Select sites that primarily run video content may have the video in a top-level marquis position. 

Once the player is in viewport, it will all start to play on automute. To ensure higher viewability, as the reader scrolls out of viewport, all video players (regardless of placement) will float to the bottom right corner of the site to remain in view and continue to play through.

Player Size

The players are displayed at either 16:9 or 4:3 aspect ratio. The optimal size for larger video players is 640×360/640×480. This is achieved primarily within the mid-stream content position. However, it is important to note this size is typically scrolled through. 

The smaller 400×300 size (served initially in the right rail) actually receives longer playthrough and more ad impressions as it is served in the bottom right corner on top of existing content.

According to a Wistia study, the “sweet spot” in video width is  between 401 pixels and 600 pixels. Videos of that size have the highest average play rate. 

And, according to the graph below, larger in-stream players actually have a similar playthrough rate as the smaller right rail players.

Please note, all of our players are responsive and will adjust to the appropriate size for mobile devices.

Overall Player Performance

The player size has less to do with playthrough than it being viewable. Keeping the videos floating once they have been viewed at the bottom right maintains the highest performance.

Content Specifications

Creating your own content? Great!

Here are the file types we can upload to your specific playlist. 

    • H.264 video codec and the AAC audio codec. (We can use H.265, however, that could limit access as it requires the viewer to be using desktop hardware released after 2015, running either Windows 10+ or Mac’s High Sierra)
    • VP8 video codec and the Vorbis audio codec. WebM is of comparable quality to MP4, but it has limited browser and device support.

Video Specs

Creating your own video content? Great! We can add that content to your Mirror Digital network player. 

While the player can convert just about any video file, there are some files that just work better. Here are some quick video specs to follow.


Here are the file types we can upload to your specific playlist. 

  • MP4 – preferred
  • .mov 
  • .flv 
  • .wmv 
  • .webM
  • .3gp 
  • .avi 


H.264 video codec and the AAC audio codec


1080p1920×108015,000 kbps256 kbps
720p1280×72010,000 kbps256 kbps
360p640×3605,000 kbps256 kbps

Want to deeper dive into specifications, check out JW documentation here.

Authorized Digital Sellers (ads.txt) – How To Update

What Is An ads.txt File?

The ADS (Authorized Digital Sellers) file is a document that lets publishers know you have agreed to sell ad inventory on your site. Learn more here.

Why Do I Need It?

The ads.txt file helps prevent unauthorized platforms from selling ad inventory on (and stealing revenue from) your site. All sites that work with Mirror Digital must have an ads.txt file on their server so that we can sell ads to your site as part of our advertising network agreement. 

What Goes In That File?

Here are Mirror Digital’s current required ads.txt entries.

How Do I Create An Ads.Txt File?

You can set up the file in several ways, depending on your needs and site CMS.

    If you have FTP access, you can add directly to your server. You or your developer can create and name the file “ads.txt,” add the lines we provide, and upload it directly to the root of your server. (i.e, domainname.com/ads.txt). This file is updated a few times a year, so you will need to reach back out to your developer each time.
    If you are on WordPress platform, you can create/update via plugin.
    We recommend WordPress users install Ads.Txt Manager plugin.
A screenshot of a menu

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  • Click here to download the plugin.
  • Once installed, activate the plugin, and go to “Settings” in your dashboard’s left-hand column. 
  • Click on “Ads.txt” to view and update the file. 
    A screenshot of a computer

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  • The first time you click on this page, it will be blank. Copy and paste the list of sellers and publisher IDs we have provided you to the file. 
  • For updates, the page will have existing copy. DO NOT delete unless specifically advised. Simply copy and paste the new info we provide directly below the existing copy. 
  • Once pasted, click “Save.” 
  • If there are any issues, it will produce an error message. If that occurs, please take a screenshot and send us the error message and we will correct and resend to you.
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  • If copied correctly, the form will update with a saved message and you are finished! 
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  1. VIA WIX
    If you are on Wix.com, you can update via dashboard. 
  • Go to the “Marketing Integrations” in your site’s dashboard. Click Connect under Ads.txt. Click Add ads.txt. Paste your list of sellers and publisher IDs and click “Save.”
  • If you already have a file created, click the “show more” button at the top to edit. DO NOT delete any existng unless specifically advised. Simply copy and paste the new info we provide directly below the existing copy.  Then click “save.”
  1. Via Mirror Digital
    If you do not have a developer, are not comfortable installing the plugin, or do not use WordPress, our team can add it for you. Please be advised that you may be charged a developer’s fee, billed in 30-minute increments, for the set-up and updates.

Once added, please confirm the information has been added correctly by visiting https://yourdomain.com/ads.txt (make sure to replace yourdomain.com with your site’s URL.)

IMPORTANT: Please note, the ads.txt file cannot be uploaded in your media backend or created as a post. You must either have FTP server access or use a plugin to create. Please also note, it can take up to 24 hours for the file to update.

Authorized Digital Sellers (ads.txt) – Files


google.com, pub-1289749092580701, DIRECT, f08c47fec0942fa0


yahoo.com, 59366, DIRECT, e1a5b5b6e3255540


g.com, 28814, RESELLER

advertising.com, 28816, RESELLER

appnexus.com, 12564, RESELLER, f5ab79cb980f11d1

indexexchange.com, 193162, RESELLER

google.com, pub-5760410923284845, RESELLER, f08c47fec0942fa0

pubmatic.com, 159247, RESELLER, 5d62403b186f2ace

pubmatic.com, 160127, RESELLER, 5d62403b186f2ace

rhythmone.com, 4245644886, RESELLER, a670c89d4a324e47

video.unrulymedia.com, 4245644886, RESELLER

Publisher Restrictions

  1. Publisher will not engage in any form of fraudulent traffic generating methods, including without limitation any measures that generate automated, fraudulent, or otherwise invalid impressions or clicks. If, in Mirror Digital’s reasonable business judgment, activity related to the Publisher Sites is suspected or determined to be so-called “click-fraud” or “impression fraud” (the illicit manipulation of advertising revenue), whether in any automated or human way, by the use of a person, an automated script or a computer program (for example, online robots or “bots”) to click on Ads, or any other fraudulent means, to increase impressions, skew results or imitate a legitimate user of a web browser reloading or clicking on an ad for the purpose of generating an improper click or impression value and generating revenue, Mirror Digital may suspend the Service until such time as the matter is resolved to Mirror Digital’s satisfaction. Mirror Digital retains the right to not credit Publisher for those clicks or impressions that it reasonably determines or suspects are fraudulent.
  2. Publisher Site shall not contain or promote content that is deemed prohibited content (e.g., violent content, sexual content, disaster content, illegal drugs/activities, obscenity, hate speech, content promoting or containing malware, or piracy of third-party material).
  3. Publisher will not attempt to interfere with or disrupt the Service (including by modification of the Ad Tags or any Ads, or the re-syndication of any Ads) or attempt to gain access to any systems or networks that connect thereto.