diff --git a/res/include/md/about.md b/res/include/md/about.md
index 53d09e1..4ff037f 100644
--- a/res/include/md/about.md
+++ b/res/include/md/about.md
@@ -185,6 +185,38 @@ be public. For that reason I disabled search indexing on all pixeldrain files.
 This protects the privacy of pixeldrain users and helps with preventing
 information leaks.
 
+## How does the affiliate program work?
+
+Pixeldrain's affiliate program is a way to earn pixeldrain credit by driving
+traffic to pixeldrain. The way it works is that you send people your affiliate
+link, if someone accepts to be your affiliate then their active subscription
+will earn you pixeldrain credit. The affiliate program is opt-in and fully
+transparent. Users will always be notified when their affiliate account is
+updated. You can update who you are sponsoring by editing the affiliate name on
+your [user settings page](/user/settings).
+
+Here is a summary of all the rules and limitations:
+
+* Each paying customer using your affiliate code will earn you €0.50 in prepaid
+  credit every month. The credit is added to your account on a daily basis, as
+  you can see on the [transactions page](/user/prepaid/transactions).
+* Sponsoring someone with an affiliate code does not cost you any extra money.
+  The resulting fee comes out of pixeldrain's pockets.
+* You can only earn pixeldrain credit with the affiliate program. There is no
+  cash out feature.
+* When someone who is using your affiliate code cancels their plan, you will
+  also stop receiving rewards.
+* You don't need an active subscription to gain credit through the affiliate
+  program. You need a positive balance of at least €1 to activate the prepaid
+  plan.
+
+Some fun facts:
+
+* You only need two affiliates to offset pixeldrain's base subscription fee.
+* Each sponsoring user is effectively equal to 125 GB of storage space or 500 GB
+  of bandwidth usage per month.
+* You cannot sponsor yourself.
+
 ## Is there a clean pixeldrain logo I can use?
 
 Yes, here's a high resolution pixeldrain logo with text. The font is called
diff --git a/svelte/src/file_viewer/FileViewer.svelte b/svelte/src/file_viewer/FileViewer.svelte
index 6962080..256c7c9 100644
--- a/svelte/src/file_viewer/FileViewer.svelte
+++ b/svelte/src/file_viewer/FileViewer.svelte
@@ -20,6 +20,7 @@ import ListStats from "./ListStats.svelte";
 import ListUpdater from "./ListUpdater.svelte";
 import CopyButton from "../layout/CopyButton.svelte";
 import Menu from "../filesystem/Menu.svelte"
+import AffiliatePrompt from "../user_home/AffiliatePrompt.svelte";
 
 let loading = true
 let embedded = false
@@ -617,6 +618,8 @@ const keyboard_event = evt => {
 
 	<!-- At the bottom so it renders over everything else -->
 	<LoadingIndicator loading={loading}/>
+
+	<AffiliatePrompt/>
 </div>
 
 <style>
diff --git a/svelte/src/filesystem/Filesystem.svelte b/svelte/src/filesystem/Filesystem.svelte
index 61f7566..675b6bf 100644
--- a/svelte/src/filesystem/Filesystem.svelte
+++ b/svelte/src/filesystem/Filesystem.svelte
@@ -14,6 +14,7 @@ import { writable } from 'svelte/store';
 import TransferLimit from '../file_viewer/TransferLimit.svelte';
 import { stats } from "../lib/StatsSocket.js"
 import { css_from_path } from './edit_window/Branding';
+import AffiliatePrompt from '../user_home/AffiliatePrompt.svelte';
 
 let file_viewer
 let file_preview
@@ -198,6 +199,8 @@ const download = () => {
 		even when the user navigates to a different directory -->
 	<FSUploadWidget nav={nav} bind:this={upload_widget} />
 
+	<AffiliatePrompt/>
+
 	<LoadingIndicator loading={$loading}/>
 </div>
 
diff --git a/svelte/src/layout/CopyButton.svelte b/svelte/src/layout/CopyButton.svelte
index 1333759..904a905 100644
--- a/svelte/src/layout/CopyButton.svelte
+++ b/svelte/src/layout/CopyButton.svelte
@@ -4,6 +4,7 @@ import { copy_text } from "../util/Util.svelte";
 export let text = ""
 export let style = ""
 export let large_icon = false
+export let small_icon = false
 let failed = false
 let success = false
 
@@ -31,6 +32,7 @@ export const copy = () => {
 	class:button_highlight={success}
 	class:button_red={failed}
 	class:large_icon
+	class:small_icon
 	title="Copy text to clipboard"
 	disabled={text === ""}
 >
@@ -55,4 +57,8 @@ export const copy = () => {
 	font-size: 40px;
 	display: block;
 }
+.small_icon>.icon {
+	font-size: 1.2em;
+	display: block;
+}
 </style>
diff --git a/svelte/src/user_home/AccountSettings.svelte b/svelte/src/user_home/AccountSettings.svelte
index bd5cd2e..7938ac4 100644
--- a/svelte/src/user_home/AccountSettings.svelte
+++ b/svelte/src/user_home/AccountSettings.svelte
@@ -1,6 +1,9 @@
 <script>
+import CopyButton from "../layout/CopyButton.svelte";
 import Form from "./../util/Form.svelte";
 
+let affiliate_link = window.location.protocol+"//"+window.location.host + "?ref=" + window.user.username
+
 let account_settings = {
 	name: "account_settings",
 	fields: [
@@ -40,6 +43,7 @@ let account_settings = {
 			description: `Changing your username also changes the name used to
 				log in. If you forget your username you can still log in using
 				your e-mail address if you have one configured`,
+			separator: true,
 		},
 	],
 	submit_label: `<i class="icon">save</i> Save`,
@@ -57,10 +61,35 @@ let account_settings = {
 		form.append("password_new", fields.password_new1)
 		form.append("username", fields.username)
 
-		const resp = await fetch(
-			window.api_endpoint+"/user",
-			{ method: "PUT", body: form }
-		);
+		const resp = await fetch(window.api_endpoint+"/user", { method: "PUT", body: form });
+		if(resp.status >= 400) {
+			return {error_json: await resp.json()}
+		}
+		return {success: true, message: "Success! Your changes have been saved"}
+	},
+}
+
+const affiliate_settings = {
+	name: "affiliate_settings",
+	fields: [
+		{
+			name: "affiliate_user_name",
+			label: "Affiliate user name",
+			type: "text",
+			default_value: window.user.affiliate_user_name,
+			description: `The affiliate user name can be the name of a
+				pixeldrain account you wish to support with your subscription.
+				The account will receive a fee of €0.50 for every month that
+				your premium plan is active. This does not cost you anything
+				extra.`,
+		},
+	],
+	submit_label: `<i class="icon">save</i> Save`,
+	on_submit: async fields => {
+		const form = new FormData()
+		form.append("affiliate_user_name", fields.affiliate_user_name)
+
+		const resp = await fetch(window.api_endpoint+"/user", { method: "PUT", body: form });
 		if(resp.status >= 400) {
 			return {error_json: await resp.json()}
 		}
@@ -102,15 +131,33 @@ let delete_account = {
 </script>
 
 <section>
-	<br/>
-	<div class="highlight_border">
-		<h3>Account settings</h3>
+	<fieldset>
+		<legend>Account settings</legend>
 		<Form config={account_settings}></Form>
-	</div>
-	<br/>
-	<div class="highlight_border">
-		<h3>Delete account</h3>
+	</fieldset>
+
+	<fieldset>
+		<legend>Affiliate settings</legend>
+		<Form config={affiliate_settings}></Form>
+		<div class="form">
+			<p>
+				Your own affiliate link is
+				<a href="{affiliate_link}">{affiliate_link}</a>
+				<CopyButton small_icon text={affiliate_link}/>. Share this link
+				with premium pixeldrain users to gain commissions. For a
+				detailed description of the affiliate program please check out
+				the <a href="/about#toc_12">Q&A page</a>.
+			</p>
+			<p>
+				Note that the link includes the name of your pixeldrain
+				account. If you change your account name the link will stop
+				working and you might stop receiving commissions.
+			</p>
+		</div>
+	</fieldset>
+
+	<fieldset>
+		<legend>Delete account</legend>
 		<Form config={delete_account}></Form>
-	</div>
-	<br/>
+	</fieldset>
 </section>
diff --git a/svelte/src/user_home/AffiliatePrompt.svelte b/svelte/src/user_home/AffiliatePrompt.svelte
new file mode 100644
index 0000000..2ecc5fd
--- /dev/null
+++ b/svelte/src/user_home/AffiliatePrompt.svelte
@@ -0,0 +1,127 @@
+<script>
+import { onMount } from "svelte";
+import Modal from "../util/Modal.svelte";
+import LoadingIndicator from "../util/LoadingIndicator.svelte";
+
+// When the always flag is set then the pop-up will also show if the user
+// already has an affiliate ID set
+export let always = false
+let modal
+let loading
+let ref
+
+onMount(() => {
+	if (!always) {
+		if (window.user.subscription.id === "") {
+			// User does not have an active subscription, setting referral will
+			// not have effect
+			return
+		} else if (window.user.affiliate_user_name !== "") {
+			// User is already sponsoring someone
+			return
+		} else if (localStorage.getItem("affiliate_deny") === "1") {
+			// User has dismissed the pop-up in the past
+			return
+		}
+	}
+
+	ref = new URLSearchParams(document.location.search).get("ref")
+	if (ref === null) {
+		return
+	} else if (ref === window.user.affiliate_user_name) {
+		return // User is already supporting this affiliate ID
+	}
+
+	modal.show()
+})
+
+const allow = async () => {
+	loading = true
+	try {
+		const form = new FormData()
+		form.append("affiliate_user_name", ref)
+		const resp = await fetch(window.api_endpoint+"/user", { method: "PUT", body: form });
+		if(resp.status >= 400) {
+			throw (await resp.json()).message
+		}
+
+		// Update the window.user variable
+		window.user.affiliate_user_name = ref
+
+		// Close the popup
+		modal.hide()
+	} catch (err) {
+		alert(err)
+	} finally {
+		loading = false
+	}
+}
+
+const deny = () => {
+	localStorage.setItem("affiliate_deny", "1")
+	modal.hide()
+}
+</script>
+
+<Modal bind:this={modal} title="Affiliate sponsoring request" width="700px">
+	<LoadingIndicator bind:loading={loading} />
+	<section>
+		<p>
+			Hi! {ref} wants you to sponsor their pixeldrain account. This will
+			give them €0.50 every month in pixeldrain prepaid credit. They can
+			use this credit to get a discount on their file sharing and storage
+			efforts. Here is a short summary of what this entails:
+		</p>
+		<ul>
+			<li>
+				Sponsoring only works while you have an active subscription
+				plan. When your subscription deactivates the creator will no
+				longer receive commissions.
+			</li>
+			<li>
+				Pixeldrain credit cannot be cashed out. So they are not earning
+				real money with this.
+			</li>
+			<li>
+				This does not cost you any extra money. The commissions paid out
+				to the creator are paid for by pixeldrain itself.
+			</li>
+			<li>
+				You can change who you are sponsoring at any time on your <a
+				href="/user/settings">account settings page</a>.
+			</li>
+			<li>
+				If you want to know more about the affiliate program check out
+				the <a href="/about#toc_12">Q&A page</a>.
+			</li>
+		</ul>
+		<p>
+			If you click 'Accept' then the requested affiliate code will be
+			added to your account and the creator will start earning. If you
+			choose 'Deny' then we will never show this pop-up again.
+		</p>
+		<div class="buttons">
+			<button class="button button_red" on:click={e => deny()}>
+				Deny
+			</button>
+			<button class="button button_highlight" on:click={e => allow()}>
+				Accept
+			</button>
+		</div>
+	</section>
+</Modal>
+
+<style>
+.buttons {
+	display: flex;
+	flex-direction: row;
+	justify-content: space-around;
+	gap: 10px;
+}
+.button {
+	flex: 1 1 auto;
+	margin: 0;
+	font-size: 1.2em;
+	justify-content: center;
+}
+</style>
diff --git a/svelte/src/user_home/Router.svelte b/svelte/src/user_home/Router.svelte
index 426776c..5c3c352 100644
--- a/svelte/src/user_home/Router.svelte
+++ b/svelte/src/user_home/Router.svelte
@@ -11,6 +11,7 @@ import BandwidthSharing from "./BandwidthSharing.svelte";
 import EmbeddingControls from "./EmbeddingControls.svelte";
 import PageBranding from "./PageBranding.svelte";
 import Dashboard from "./dashboard/Dashboard.svelte";
+import AffiliatePrompt from "./AffiliatePrompt.svelte";
 
 let pages = [
 	{
@@ -88,3 +89,5 @@ let pages = [
 </script>
 
 <TabMenu pages={pages} title="Welcome, {window.user.username}!"/>
+
+<AffiliatePrompt always/>
diff --git a/svelte/src/user_home/Transactions.svelte b/svelte/src/user_home/Transactions.svelte
index 2d90c07..e4c3b41 100644
--- a/svelte/src/user_home/Transactions.svelte
+++ b/svelte/src/user_home/Transactions.svelte
@@ -16,6 +16,7 @@ let transactions = {
 	total_storage_charge: 0,
 	total_bandwidth_used: 0,
 	total_bandwidth_charge: 0,
+	total_affiliate_amount: 0,
 	total_deposited: 0,
 	total_deducted: 0,
 }
@@ -42,6 +43,7 @@ const load_transactions = async () => {
 			total_storage_charge: 0,
 			total_bandwidth_used: 0,
 			total_bandwidth_charge: 0,
+			total_affiliate_amount: 0,
 			total_deposited: 0,
 			total_deducted: 0,
 		}
@@ -54,6 +56,7 @@ const load_transactions = async () => {
 			month.total_storage_charge += row.storage_charge
 			month.total_bandwidth_used += row.bandwidth_used
 			month.total_bandwidth_charge += row.bandwidth_charge
+			month.total_affiliate_amount += row.affiliate_amount
 			month.total_deducted += row.subscription_charge + row.storage_charge + row.bandwidth_charge
 		})
 
@@ -139,6 +142,9 @@ onMount(() => {
 		<li>
 			Total charge: <Euro amount={transactions.total_deducted} precision="4"/>
 		</li>
+		<li>
+			Affiliate rewards: <Euro amount={transactions.total_affiliate_amount} precision="4"/>
+		</li>
 		<li>
 			Deposited: <Euro amount={transactions.total_deposited} precision="4"/>
 		</li>
@@ -153,6 +159,7 @@ onMount(() => {
 					<td>Subscription</td>
 					<td>Storage</td>
 					<td>Bandwidth</td>
+					<td>Affiliate</td>
 					<td>Deposit</td>
 				</tr>
 			</thead>
@@ -176,6 +183,10 @@ onMount(() => {
 							<Euro amount={row.bandwidth_charge} precision="6"/>
 							({formatDataVolume(row.bandwidth_used, 3)})
 						</td>
+						<td>
+							<Euro amount={row.affiliate_amount} precision="6"/>
+							({row.affiliate_count})
+						</td>
 						<td>
 							<Euro amount={row.deposit_amount}/>
 						</td>
diff --git a/svelte/src/user_home/dashboard/CardPrepaidTransactions.svelte b/svelte/src/user_home/dashboard/CardPrepaidTransactions.svelte
index 62d57b9..38c1d43 100644
--- a/svelte/src/user_home/dashboard/CardPrepaidTransactions.svelte
+++ b/svelte/src/user_home/dashboard/CardPrepaidTransactions.svelte
@@ -17,6 +17,7 @@ let transactions = {
 	total_storage_charge: 0,
 	total_bandwidth_used: 0,
 	total_bandwidth_charge: 0,
+	total_affiliate_amount: 0,
 	total_deposited: 0,
 	total_deducted: 0,
 	balance_start: 0,
@@ -45,6 +46,7 @@ const load_transactions = async () => {
 			total_storage_charge: 0,
 			total_bandwidth_used: 0,
 			total_bandwidth_charge: 0,
+			total_affiliate_amount: 0,
 			total_deposited: 0,
 			total_deducted: 0,
 			balance_start: 0,
@@ -66,6 +68,7 @@ const load_transactions = async () => {
 			month.total_storage_charge += row.storage_charge
 			month.total_bandwidth_used += row.bandwidth_used
 			month.total_bandwidth_charge += row.bandwidth_charge
+			month.total_affiliate_amount += row.affiliate_amount
 			month.total_deducted += row.subscription_charge + row.storage_charge + row.bandwidth_charge
 		})
 
@@ -148,6 +151,12 @@ onMount(() => {
 				(used {formatDataVolume(transactions.total_bandwidth_used, 3)})
 			</td>
 		</tr>
+		<tr>
+			<td>Affiliate rewards</td>
+			<td>
+				<Euro amount={transactions.total_affiliate_amount} precision="4"/>
+			</td>
+		</tr>
 		<tr>
 			<td>Deposited</td>
 			<td><Euro amount={transactions.total_deposited} precision="4"/></td>