What is OTT Advertising? A Beginner’s Guide

Advertising-supported video on demand, or AVOD, lets viewers watch for free while the business earns money from advertisements inserted into the content. It is the streaming equivalent of free-to-air television: the audience pays with their attention rather than their wallet. For services that prioritize scale and reach over per-user revenue, advertising is often the fastest way to grow.

How ads get into a stream

Points in the video are marked as ad opportunities, typically before the content starts (pre-roll), during natural breaks (mid-roll), or at the end (post-roll). When a viewer reaches one of these markers, the player or the server requests an ad from an ad server using an industry standard such as VAST or VMAP, and the returned advertisement is played before the content resumes.

There are two broad approaches. Client-side insertion asks the viewer's player to fetch and play the ad, which is simple to set up but easier for ad-blockers to interfere with. Server-side ad insertion, or SSAI, stitches the advertisement directly into the video stream on the server so it arrives as one seamless feed. SSAI is harder to block, starts more smoothly, and generally produces higher completion rates, which is why premium services prefer it.

Key building blocks of ad monetization

• An ad server or supply-side platform that decides which ad to serve
• Standards such as VAST, VMAP, and VPAID that describe ad placements
• Frequency capping so the same viewer is not shown one ad repeatedly
• Targeting that matches ads to audience segments for higher value
• Reporting on fill rate, completion, and revenue per thousand views

Getting the ad load right

The central tension in AVOD is between revenue and experience. More ad breaks mean more inventory to sell, but too many will drive viewers away and ultimately reduce total watch time and revenue. The goal is to find an ad load that monetizes well while keeping audiences engaged, and to always have a fallback house ad ready so a slot never plays as an empty black screen when paid demand is low.

Common questions about AVOD

How is AVOD different from FAST?

Both are ad-supported and free to the viewer. AVOD is on demand: the viewer picks what to watch. FAST is linear: always-on channels with a fixed schedule that viewers tune into. Many operators run both, using AVOD for their catalog and FAST channels for lean-back viewing.

Can a free tier coexist with a paid one?

Absolutely. A hybrid model offering a free ad-supported tier and a paid ad-free tier is now one of the most common strategies, because it monetizes both price-sensitive and premium audiences from the same catalog.