--- title: "What Is a Recommendation Engine? Definition and Examples" description: "A recommendation engine suggests what each viewer should watch next. See the main methods, the cold-start problem and how to tell whether it works." url: "https://www.rentanott.com/glossary/recommendation-engine" markdown_url: "https://www.rentanott.com/glossary/recommendation-engine.md" category: "Platform" updated: "2026-10-05" --- # What is a recommendation engine? A recommendation engine is the system that chooses which titles to suggest to each viewer, based on what they and similar viewers have watched and on the properties of the titles themselves. It fills rows such as recommended for you and because you watched. ## How recommendations are made Most services combine several of these and decide both which rows to show and the order of titles within each row. - Collaborative filtering: viewers who watched what you watched also watched this - Content-based: this title shares a genre, cast, mood or theme with ones you finished - Popularity and trending: what many people are watching now - Editorial: collections chosen by people - Contextual: adjusted for device, time of day and profile ## The cold-start problem A new viewer has no history, and a new title has no audience yet. For new viewers, start from popular and editorial choices, or ask for a few preferences at sign-up. For new titles, rely on metadata until viewing data builds up. A small or new service leans more on content-based and editorial methods for the same reason. ## Why it matters and how to judge it A viewer who cannot find a second thing to watch leaves. Good recommendations shorten the time between opening the app and pressing play, and spread viewing beyond the few titles on the front page. Judge it by outcomes: the share of plays that began from a recommended row, time to first play, and whether viewers shown recommendations watch more and stay longer. ## Recommendation engine on RentAnOTT Personalized discovery, with recommendations, watchlists and continue watching, is part of the engagement features on RentAnOTT. AI semantic search is a $59/month add-on. [See features](https://www.rentanott.com/features). ## Related terms - [Semantic search](https://www.rentanott.com/glossary/semantic-search) — Semantic search is search that matches the meaning of a query instead of its exact words. On a streaming service it lets a viewer type something like a feel-good film about food and get relevant titles, even when none of those words appear in a title or its tags. - [Content metadata](https://www.rentanott.com/glossary/content-metadata) — Content metadata is the information that describes a video title and governs how it is presented and used: its title, synopsis, cast, genre, rating, artwork, languages, rights and technical details. It is what makes a file into a catalog entry. - [Completion rate](https://www.rentanott.com/glossary/completion-rate) — Completion rate is the percentage of plays of a video that reach the end, or a defined point near it. It shows whether a title holds the people who start it. ## Further reading - [Pricing](https://www.rentanott.com/pricing) - [Short video applications compared](https://www.rentanott.com/blogs/best-short-video-application) - [OTT solution guide](https://www.rentanott.com/blogs/ott-solution) ## Frequently asked questions ### Does a small catalog need a recommendation engine? Less than a large one. With a few hundred titles, good editorial rows and a continue-watching row do most of the work; personalization pays off as the catalog grows. ### What data does a recommendation engine use? Viewing history, completion, ratings, searches and watchlist additions, combined with each title's metadata. ### Are separate profiles important for recommendations? Yes. Without profiles, one account mixes the viewing of a whole household, and the suggestions suit nobody. All 163 terms: [Streaming and OTT glossary](https://www.rentanott.com/glossary). ## Book a demo Tell RentAnOTT what you are launching. The team walks through the platform and maps the path to go-live around your catalog, markets and revenue model. Book a demo: https://www.rentanott.com/contact ## More from RentAnOTT - [Home](https://www.rentanott.com/index.md) — What RentAnOTT is, what every plan includes, and how launch works - [Features](https://www.rentanott.com/features.md) — Every core feature and optional add-on - [Pricing](https://www.rentanott.com/pricing.md) — Platform tiers, apps, add-ons, usage rates and example bills in INR and USD - [Free tools](https://www.rentanott.com/tools.md) — OTT app builder and calculators for streaming revenue, bandwidth, bitrate and pricing - [Insights](https://www.rentanott.com/blogs.md) — All streaming business articles - [Glossary](https://www.rentanott.com/glossary.md) — Definitions of streaming and OTT terms - [Book a demo](https://www.rentanott.com/contact.md) — Talk to RentAnOTT about your launch Full site in one file: https://www.rentanott.com/llms-full.txt