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CTV and OTT reporting

How Pixalate classifies OTT content and CTV devices, and how it treats server-side ad insertion (SSAI).

Pixalate classifies over-the-top (OTT) advertising by the device the ad was shown on, not by the content being watched. This page explains the definitions, how mirrored and cast content is classified, and how Pixalate handles server-side ad insertion (SSAI), which is common in connected TV (CTV).

OTT and CTV

Pixalate’s definitions generally follow the IAB Tech Lab’s CTV and OTT definitions.

TermMeaning
OTT”Over-the-top”: accessing TV content without a regular TV set-top box. The content is delivered over an internet connection rather than through a traditional cable or broadcast provider.
OTT contentContent that can be consumed on many devices, including desktops, laptops, mobile devices and CTV devices.
CTV deviceAny device that isn’t a desktop, laptop or mobile device and is used to consume OTT content. Examples include smart TVs, Apple TV, Chromecast, PlayStation, Xbox, Amazon Fire TV sticks and other streaming devices.

In short, CTV describes the device connected to the internet: either a TV with internet capabilities or a device that connects to the internet and uses a TV to display content. OTT describes the content delivered over the internet, which can also reach mobile devices and browsers.

Pixalate avoids the term “OTT device”, because it mixes the two ideas.

How traffic is classified

Pixalate categorizes OTT ad inventory based solely on the device on which its measurement tags fire.

ScenarioClassified as
Watching Sling TV on a smartphoneMobile. It’s OTT content, but not on a CTV device.
Watching Sling TV on an Apple TVCTV
Watching on a smart TVCTV
Mirroring a laptop to an Apple TV while watching OTT contentThe laptop, not CTV. The ad is served on the laptop, so the laptop is the device.
Pressing Cast in YouTube on a laptop to send the content to a ChromecastCTV. The Chromecast becomes the primary device, so ads it serves are classified as CTV.

Mirroring and casting differ in which device serves the ad. When you mirror, the laptop still plays the content and serves the ads, and the TV only displays the laptop’s screen. When you cast, the streaming device, such as Chromecast, takes over through its integration with the app.

MRC accreditation for CTV

Pixalate is currently MRC accredited for OTT / CTV in the following areas:

  • Display Served Impressions
  • Video Served Impressions
  • SIVT detection and filtration for both Display and Video Impressions

For Pixalate’s full, current accreditation scope, see MRC accreditation.

Server-side ad insertion (SSAI)

SSAI, also known as dynamic ad insertion or ad stitching, delivers ads from the server side. Traditionally, video content comes from a content delivery network (CDN) on the server side, while video ads come from a third-party ad server on the client side. With SSAI, the video provider stitches the content and the ads together on the server side.

Impressions are typically tracked on the client side: a tracking pixel in the creative fires when the creative renders. SSAI makes this more complex, depending on the architecture, because:

  • The proxy server takes over some client functions, such as firing tracking pixels on behalf of the client.
  • The standard HTTP headers that identify a client, such as the IP address and user agent, belong to the proxy server instead. Additional headers, which are currently optional, are needed to pass the user’s information to third-party measurement companies.

Legitimate use

Video content providers use SSAI for a more seamless viewing experience. If CTV ads keep buffering, viewers may move back to traditional TV. SSAI serves the content and ads without interruption.

How fraudsters use SSAI

Mismatched IP addresses have traditionally been a risk signal, but in CTV there’s a legitimate reason for them: SSAI. Fraudsters use this. The easiest way to change an IP address is through a proxy server, so fraudsters hide behind SSAI and spoof or fake inventory by altering the information in the ad request. Because the request comes from a proxy, it’s hard to verify that the information is legitimate.

Depending on the SSAI architecture, an SSAI proxy server may compose all HTTP requests on behalf of the end user. Machines can act as proxies and fake the user’s request headers, such as X-Forwarded-For, X-Device-User-Agent and the Forwarded HTTP extension. SSAI detection that relies only on X-Forwarded-For headers is therefore extremely error prone.

How Pixalate detects SSAI and decides whether it’s IVT

Pixalate doesn’t treat all SSAI as invalid traffic (IVT), because SSAI is used for both legitimate and fraudulent purposes. It decides for each transaction.

When Pixalate detects SSAI, it takes an additional step to determine whether the traffic is invalid. Pixalate has created and analyzed more than 30 composite signals that characterize the behavior of an SSAI server and its interactions with the publisher (for example, apps) and the client (for example, device ID). These signals let Pixalate tell real SSAI from fake, estimate the reputation of an SSAI server, and determine whether an SSAI proxy generates valid or invalid traffic.

To see your SSAI traffic in reports, use the SSAI metrics.

Common IVT types in CTV

Reported typeWhat it looks like in CTV
ProxyInvalid SSAI. For example, the client’s IP doesn’t match the IP detected when the ad renders, and the proxy IP is determined to be invalid.
Video Impression FraudStatistically significant outlier user behavior, detected with Pixalate’s algorithms and machine-learning models. It can occur on any device, including CTV.
DatacenterTraffic from an IP address identified as a data center. For example, hundreds of jailbroken CTV devices set up to play content continually on a specific app or group of apps.
IP ObfuscationA proxy IP is discovered, but a cookie extends to a statistically inflated number of unique device IDs or IPs. This can be a sign of a desktop device masquerading as a CTV device.
App SpoofingTraffic from apps that appear to be spoofed, at the impression level or at more macroscopic levels.

For each type’s class and its match in IVT Taxonomy 2.0, see Reported IVT types.

Protect CTV traffic

Questions? Contact support@pixalate.com.