diff --git a/includes/class-admin.php b/includes/class-admin.php
index 8b2c933..649b59c 100644
--- a/includes/class-admin.php
+++ b/includes/class-admin.php
@@ -17,6 +17,9 @@ class WC_EDM_Admin {
 	/**
 	 * Admin page slug.
 	 */
+	/** Cache key for the dashboard card's counts. */
+	const CARD_TRANSIENT = 'wc_edm_card_counts';
+
 	const PAGE_SLUG = 'wc-email-discounts';
 
 	/**
@@ -59,10 +62,60 @@ class WC_EDM_Admin {
 		$this->audit    = class_exists( 'WC_EDM_Admin_Audit' ) ? new WC_EDM_Admin_Audit() : null;
 
 		add_action( 'admin_menu', array( $this, 'register_menu' ) );
+		add_filter( 'wpmgr_dashboard_cards', array( $this, 'dashboard_card' ) );
 		add_action( 'admin_init', array( $this, 'handle_actions' ) );
 		add_action( 'admin_enqueue_scripts', array( $this, 'enqueue_assets' ) );
 	}
 
+	/**
+	 * This plugin's card on the shared Nolimit dashboard.
+	 *
+	 * The contract says implementations must not measure anything here,
+	 * because this filter runs on an admin page load and a slow card makes
+	 * somebody else's dashboard slow in a way they cannot attribute. Two
+	 * COUNT(*) on small indexed tables is the most this may cost, and even
+	 * that is cached: the dashboard is a page people leave open.
+	 *
+	 * @param array $cards The cards so far.
+	 * @return array
+	 */
+	public function dashboard_card( $cards ) {
+		$counts = get_transient( self::CARD_TRANSIENT );
+
+		if ( ! is_array( $counts ) ) {
+			$counts = array(
+				'groups' => WC_EDM_DB::count_groups(),
+				'emails' => WC_EDM_DB::count_emails( true ),
+			);
+			set_transient( self::CARD_TRANSIENT, $counts, 5 * MINUTE_IN_SECONDS );
+		}
+
+		// "warn", not "fail": a shop that has installed this and not set it up
+		// yet is not broken, it is unfinished. Reserving red for actual
+		// breakage is what keeps red worth reading.
+		$status = $counts['groups'] > 0 && $counts['emails'] > 0 ? 'ok' : 'warn';
+
+		$cards[] = array(
+			'title'    => __( 'Discounts', 'wc-email-discount' ),
+			'status'   => $status,
+			'headline' => sprintf(
+				/* translators: %s: number of email addresses that currently receive a discount. */
+				_n( '%s address gets a discount', '%s addresses get a discount', $counts['emails'], 'wc-email-discount' ),
+				number_format_i18n( $counts['emails'] )
+			),
+			'lines'    => array(
+				__( 'Groups', 'wc-email-discount' )            => number_format_i18n( $counts['groups'] ),
+				__( 'Active addresses', 'wc-email-discount' )  => number_format_i18n( $counts['emails'] ),
+			),
+			'url'      => admin_url( 'admin.php?page=' . self::PAGE_SLUG ),
+			// The plugin's own colour. Deliberately not WooCommerce's brand
+			// purple; see the note in assets/icon.svg.
+			'colour'   => '#1a7a52',
+		);
+
+		return $cards;
+	}
+
 	/**
 	 * Register the page under the shared Nolimit menu.
 	 *
diff --git a/tests/smoke.php b/tests/smoke.php
index 8acd4a1..842783e 100644
--- a/tests/smoke.php
+++ b/tests/smoke.php
@@ -287,6 +287,33 @@ wc_edm_ok(
 	'it is not in the is_admin() branch of includes(), so nothing would define wpmgr_ensure_menu()'
 );
 
+// The card on the shared dashboard. Absent from it is a different failure from
+// absent from the menu, and Kristian hit both in turn: the menu entry missing,
+// then the card missing once the entry was there.
+$wc_edm_cards = apply_filters( 'wpmgr_dashboard_cards', array() );
+$wc_edm_mine  = array_values(
+	array_filter(
+		$wc_edm_cards,
+		static function ( $card ) {
+			return isset( $card['url'] ) && false !== strpos( $card['url'], WC_EDM_Admin::PAGE_SLUG );
+		}
+	)
+);
+wc_edm_ok(
+	'this plugin puts a card on the shared dashboard',
+	1 === count( $wc_edm_mine ),
+	count( $wc_edm_cards ) . ' card(s) registered in total'
+);
+
+// Matched against the literal rather than the constant: the shared file
+// renders any colour it is handed, so a card asserting its own constant would
+// agree with itself after somebody put WooCommerce purple back.
+wc_edm_is(
+	'and it carries this plugin colour, not WooCommerce purple',
+	'#1a7a52',
+	isset( $wc_edm_mine[0]['colour'] ) ? $wc_edm_mine[0]['colour'] : null
+);
+
 // includes/shared-menu.php is byte-identical in all five plugins, and which
 // copy a site loads is decided by activation order. Editing it here would make
 // a site with three of five updated show one label or another depending on who