> ## Documentation Index > Fetch the complete documentation index at: https://docs.almedia.dev/llms.txt > Use this file to discover all available pages before exploring further. # Glossary > The terms used across this site, in plain language — attribution, postbacks, the three Link experiences, and the measures Almedia reports on. Integration work spans three vocabularies: yours, your MMP's, and Almedia's. This page is the shared one. Every entry links to the page that covers it properly. ## Attribution Working out which campaign a player came from. Your MMP does this. Almedia Link does not need a player to be attributed — see [unattributed postback](#unattributed-postback). ## CPA Cost per action. The fixed amount Almedia pays for one completed action — most often a verified link. Rates are agreed with your account manager, not published. See [how revenue works](https://docs.almedia.dev/overview/how-revenue-works.md). ## Deep link A link that opens a specific place inside your game rather than the store page. Link uses one to return a player to your game after they finish linking. See [prerequisites](https://docs.almedia.dev/publisher/prerequisites.md). ## Earn Tab See [Offers](#offers-earn-tab). ## Freecash The rewards platform players link their account to. Almedia funds the rewards paid there — they do not come out of your economy. See [what is Almedia Link](https://docs.almedia.dev/overview/what-is-almedia-link.md). ## Holdout group A slice of players randomly held back from seeing Link, used to measure what Link actually added rather than what correlated with it. Almedia runs these automatically, server-side. ## IAA In-app advertising revenue — what a game earns from ads. A "high-IAA game" earns mostly from ads rather than purchases, which matters because ad revenue is the main thing players are scored on. See [verify attribution](https://docs.almedia.dev/qa/verify-attribution.md). ## IAP In-app purchase revenue — what a game earns from players buying things. ## Install-to-link rate The share of players who install your game and go on to link a Freecash account. The average across live integrations is **\~15%**. It is the main number a placement is judged on. See [best practices](https://docs.almedia.dev/overview/best-practices.md). ## Integration key The credential that identifies your app to the SDK. Almedia issues one per platform, so an iOS build and an Android build each carry their own. See [get started](https://docs.almedia.dev/overview/get-started.md). ## Link Two meanings on this site. Capitalised, **Link** is the product. Lowercase, a **link** is one player connecting their Freecash account to your game — the thing a CPA is paid for. ## Link Coins The score in the [best practices](https://docs.almedia.dev/overview/best-practices.md) checklist. A self-assessment device for rating your own placement, not a player-facing currency and not money. ## LTV Lifetime value — total revenue expected from a player over their life in your game. Linked players show a **10%+ lift**, which is the second reason to run Link beyond the CPA itself. ## Milestone A step in a player's reward progression that pays out when reached. Which milestones exist, and what each pays, is set per campaign. ## MMP Mobile measurement partner — the attribution tool your game already uses. Almedia supports [Adjust](https://docs.almedia.dev/publisher/mmp/adjust.md), [AppsFlyer](https://docs.almedia.dev/publisher/mmp/appsflyer.md) and [Singular](https://docs.almedia.dev/publisher/mmp/singular.md). Almedia reads your MMP's events to know what a linked player is doing, which is how rewards get scored. ## Offers (Earn Tab) The experience that shows other games a player can install and earn from, inside your game. It pays a separate CPA on top of the link itself. See [experiences](https://docs.almedia.dev/publisher/experiences.md). ## Offerwall A placement showing many paid offers, competing with rewarded video for the same attention. **Link is not an offerwall** — it sits on top of your existing monetisation rather than replacing any of it. See [what is Almedia Link](https://docs.almedia.dev/overview/what-is-almedia-link.md). ## Postback A server-to-server message from your MMP telling Almedia that something happened — an install, a session, a purchase, ad revenue. Almedia cannot score a player's progress without them. See [verify attribution](https://docs.almedia.dev/qa/verify-attribution.md). ## Probabilistic modeling An Adjust attribution setting that fills gaps where a deterministic match is unavailable. It has to be on for Link. See [Adjust setup](https://docs.almedia.dev/publisher/mmp/adjust.md). ## Rewarded Progression The in-game screen listing what a player has to do in your game, their progress against each task, and what they have earned on Freecash. Also written **Reward Progression** on this site. See [experiences](https://docs.almedia.dev/publisher/experiences.md). ## S2S Server-to-server. Describes a direct integration between two backends, with no device in the middle — how postbacks travel. ## Unattributed postback An event for a player your MMP could not tie to a campaign — most organic players. **Almedia needs these specifically.** Sending only attributed events is the single most common reason a new integration looks broken. See [prerequisites](https://docs.almedia.dev/publisher/prerequisites.md). This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.