For online publishers mobile traffic serves as a serious monetization headache. Less ad inventory available per page view is creating new ways of expanding publishers’ already slim profit margins. Mobile RTB ad exchanges are a great solution.

mopub mobile rtb marketplace

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Before we get down to your top 10 list we should probably say a little something about what RTB is, how it works, and how you can benefit from using RTB ad exchanges to monetize mobile traffic.

What is RTB?

RTB is a process of bidding on ad inventory in an ongoing, instantaneous auction. When a user visits a webpage, creating an ad impression, the page data is sent to an ad exchange, where advertisers can compete in an auction for each impression.

The highest bidding advertiser earns the impression and their ad is displayed on the website in real time. Instead of paying in advance for the ad inventory, like with a traditional media buy, the advertiser can choose which impressions to purchase at the exact time they need them.

fast rtb for mobile

For advertisers, RTB means there’s no need to purchase a large volume of impressions to place advertisements on a website — instead, they can bid on impressions in real time, pretty cool, right?! And think of the possibilities. Advertisers can also use RTB marketplaces to avoid interacting directly with publishers who want to negotiate CPM rates and minimum ad purchases.

As a result, advertisers can choose exactly where and how to advertise, improving their ability to reach their exact audience. Fewer impressions are wasted, less money is spent on low-value ad impressions, and advertisers achieve a better return on ad spend from their campaigns. No wonder it’s so darn popular.

RTB isn’t just for advertisers — it’s also some really cool benefits for publishers. With an RTB marketplace, a publisher can offer a certain amount of their traffic for real time bidding, while also setting a price floor that prevents their RPM from dropping below what they can achieve using an ad network.

The end result is that advertisers can programmatically buy the traffic they need at a competitive price without any of volume restrictions set by a network and publishers can increase their ad earnings by selling ad impressions through a real-time marketplace that can maximize yield per each ad impression.

That’s it for our explanation of RTB but if you’re interested in learning more about real-time bidding and how to make it work for you then check out our post, The Publisher Side: 5 Real Time Bidding Insider Secrets for 2016, for insider information and tips on how you can earn more from your ad inventory using RTB marketplaces.

What is an ad marketplace?

An ad marketplace connects publishers with advertisers. As a publisher, selling ad impressions through an RTB marketplace lets advertisers compete for your inventory. Theoretically, the more advertisers bid for ad impressions on your website, the higher your average RPM will become.

Imagine a stock exchange floor, where stocks are sold to the highest bidder through a system of signals and deals. Now imagine a similar scene, but instead of only trading stocks, we’re trading ad inventory across a huge variety of websites and apps.

There’s a supply of ad inventory, provided by publishers. On the other side, there’s demand for this ad inventory, provided by advertisers eager to display their ads to people.

suplly and demand online advertising marketplace

The more desirable inventory is for an advertiser and the greater the amount of competition for the inventory, the more the publisher will earn. Websites that attract a desirable audience could earn a lot from an RTM marketplace, since several advertisers will try to outbid each other.

On the other hand, websites that don’t attract a particularly desirable audience might barely get any attention at all and have to deal with low CPM bids for their ad inventory.

There are lots of RTB marketplaces out there, ranging from small, vertical-specific marketplaces to marketplaces aimed at specific devices. Most ad marketplaces are fairly transparent and give publishers access to some data on CPM bids and the ad creatives displayed on their websites.

What is an RTB ad marketplace?

Remember our stock exchange scene above? Replace the buyers and sellers with an algorithm designed to automate the entire process of buying and selling ad inventory, and you have an RTB ad marketplace.

open rtb marketplace diagram

Image courtesy of Ad Metrics Media

How is an RTB marketplace different from an ad network?

The 1990s introduced us to a number of new problems, like not being able to use the phone because someone is using the Internet, fitting all your favorite songs on one CD, or that little ball inside your mouse suddenly decided to stop rolling for no apparent reason.

90s meme problems

The 90s were also when advertisers couldn’t purchase inventory on a huge variety of websites, without developing relationships with thousands of publishers directly and managing those relationships through agencies, agents, or in-house employees.

Ad networks put an end to all that. Networks courted publishers and attracted advertisers by selling inventory in bulk, and collecting a cut on each ad inventory sale along the way.

Most (but not all) ad networks manage aspects of a campaign like CPM bidding, targeting and conversion optimization internally. An advertiser buys a specific amount of traffic, giving control of the campaign to the ad network and receiving traffic and reporting in return.

RTB marketplaces differ from ad networks in that advertisers bid on inventory directly from each publisher, without a third party managing their campaign for them. Advertisers have control over everything from CPM bidding to frequency capping, geotargeting and more from a self-served platform.

This means increased transparency and also access to more SSPs than an ad network can offer, although many ad networks nowadays offer their marketplaces.

The difference between an RTB marketplace and an ad network:

  1. Real-time bidding
  2. Increased control
  3. More optimization available
  4. Increased transparency
  5. Access to more SSPs

Why Mobile?

Back to the future, in 2016, it’s all about mobile. For the past two years, the number of mobile users has exceeded desktop users worldwide. With so many eyeballs focused on mobile screens it’s natural that many advertisers would migrate their ad spend to mobile.

That being said, there has been some criticism that figures demonstrating the proliferation of mobile usage are exaggerated. While that may have been true till 2015, recent studies have shown that for American consumers not only do mobile devices outnumber desktop devices but time spent on mobile devices is higher than time spent on desktops.


It’s clear that an advertiser that wants to reach his or her audience everywhere they are has to be on mobile. But, the mobile screen is much smaller than the desktop one, which means less ad inventory and less viewable ad impressions to sell.

So we have a combination of two things:

  1. Increasing number of mobile users spending an increasing amount of time on mobile devices.
  2. Less viewable ad impressions.

Less ad impressions available for increasing proportions of’ traffic is a huge red flag for online publishers and has them scrambling to find solutions to their mobile monetization woes.

With programmatic media buying (i.e. RTB) on the rise, it’s only natural that RTB marketplaces would be mobilized (get it?!) to increase revenue from mobile traffic.

How can you benefit from using a mobile RTB marketplace?

If your website attracts a high proportion of mobile traffic that advertisers are willing to pay a premium to reach, selling ad impressions through an RTB marketplace could help you achieve a higher RPM from your traffic.

By setting a reserve price for your mobile ad inventory, you can use an RTB marketplace to make sure you maximize your revenue despite have less inventory. You can even sell some of your ad inventory at a higher-than-average price, all while selling the remaining ad inventory through an ad network or AdSense as a fall back..

The top 10 mobile real-time bidding marketplaces:

smaato logo

Smaato is the world’s largest independent mobile ad marketplace, with over 260 demand-side platforms and 190+ integrated ad networks in addition to its private ad marketplace. Publishers have full control over monetization, with minimum pricing options and built-in optimization.

One of Smaato’s biggest benefits for publishers is that it works extensively to optimize for the highest possible RPMs. SPX uses “super auctions” to find the best demand source for every impression, letting publishers get the highest possible yield for each pageview.

mopub logo

Built specifically for mobile publishers, MoPub is an RTB marketplace aimed at app developers looking to sell ad inventory. The MoPub Marketplace calls itself the “largest RTB exchange for mobile apps” and is built to help publishers easily manage their mobile ad inventory.

Using MoPub, publishers can identify top-performing sources of demand in a variety of OSes and countries. MoPub also lets publishers transparently see which advertisement is winning each auction, giving them a direct look at the ad creatives displayed within their apps.

axonix logo

Axonix is an RTB mobile ad exchange designed to assist mobile publishers in optimizing their ad inventory sales. The exchange works with hundreds of DSPs and thousands of advertisers, from direct marketers to large brands.

Publishers have full control over pricing and can set price floors on an ad unit and geographic level. It’s also possible to give certain demand partners preferential access, or to block certain brands and competitors from bidding on your ad inventory.

doubleclick ad exchange

DoubleClick Ad Exchange is a global ad marketplace for ad networks, agencies and third-party demand-side platforms. Although it’s not strictly mobile (it also auctions desktop inventory) the DoubleClick Ad Exchange is one of the largest RTB marketplaces for publishers.

Interesting features of AdX include a dynamic price floor, which automatically adjusts the price floor for ad inventory based on demand from buyers, and more than 40 unique data signals for advertisers.

Vdopia Logo

Vdopia is a mobile video ad marketplace that delivers more than 32 billion ad impressions on a monthly basis. Vdopia’s “Chocolate” video ad platform allows publishers to serve video ads on any type of mobile display ad inventory.

Video ads served by Vdopia are auto-initiated and have sound disabled by default, making them ideal for increasing CPM rates without negatively affecting user experience. The ad marketplace integrates using an SDK or ad tags for mobile app developers and publishers.

adxperience logo

Adxperience is a mobile ad marketplace that’s connected with a variety of global ad exchanges and networks. Unlike certain other RTB marketplaces, Adxperience works with incentivized and non-incentivized publishers.

Advertisers can run display and push campaigns through Adxperience, giving publishers a wide variety of ways to monetize their traffic. Based in France and Israel, Adxperience delivers traffic from more than 180 countries on a daily basis.

flurry logo

Flurry Marketplace is a real-time ad bidding platform created by Flurry, which was acquired by Yahoo in 2014. Thanks to the huge amount of data Flurry has through its analytics software, it has one of the most detailed data sets available for mobile advertisers.

Since advertisers can target users based on specific factors like age and gender, Flurry’s RTB marketplace is an appealing option for advertisers. This detailed targeting could also result in higher than average eCPMs for mobile ad publishers.

mobfox logo

MobFox is an international mobile RTV marketplace with more than 30 ad network integrations, dynamic floor pricing and total control over displayed ad creatives for publishers. With a simple SDK, incorporating MobFox into your mobile app is a quick and easy process.

With support for banners, interstitial ads, video content and native ad units, MobFox is built for a huge range of mobile apps. MobFox is designed to work alongside other ad networks to deliver the highest possible eCPM by only displaying RTB ads that earn you a premium.

openx logo

OpenX isn’t exclusively a mobile ad marketplace — a large percentage of its traffic comes from desktop users — but it’s a large, highly powerful exchange that belongs in any large publisher’s monetization toolkit.

Used by 100% of the Ad Age top 100 leading advertisers and more than 70 of ComScore’s top 100 publishers, OpenX has a variety of premium advertisers and established brands willing to pay top dollar to reach high quality audiences.

one by aol logo

ONE by AOL: Mobile is AOL’s new mobile ad marketplace — a real-time bidding ad exchange for mobile that allows publishers to access a huge portfolio of leading brands and direct advertisers to monetize their mobile apps and content.

With transparent reporting and controls for publishers and AOL’s access to some of the world’s most well-known brands, ONE is a good option for mobile publishers that want to attract brands and established advertisers.

RTB and Header Bidding

RTB only works if there is a single auction for the impression where all bids are compared at the same time to quickly determine the highest and second-highest (winning) bid. Header bidding, which is another monetization solution that is gaining popularity, relies on parallel auctions bids to compete against demand from other marketplaces.

If a publisher is running an RTB marketplace and using header bidding as well then this can result in bid “replication.” We’re not going to get into the complexity of running header bidding and RTB marketplaces congruently.

The point is that RTB marketplaces are likely going to change the way they work to accommodate for header in the not so distant future.

Finally, If you have enough quality traffic to qualify for an RTB marketplace and are not using one right now then any of the above choices are a good place to start.

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