diff --git a/ads.js b/ads.js
index 48c95c0..a132a92 100644
Binary files a/ads.js and b/ads.js differ
diff --git a/public/my.html b/public/my.html
index 81d49f6..8274de8 100644
--- a/public/my.html
+++ b/public/my.html
@@ -1037,7 +1037,7 @@
 <script src="/assets/common.js?v=20260916a"></script>
 <script src="/assets/wallet.js?v=20260911a"></script>
 <script src="/assets/promo.js?v=20260911a"></script>
-<script src="/assets/my.js?v=20260918c"></script>
+<script src="/assets/my.js?v=20260918d"></script>
 <script src="/assets/chat.js?v=20260907l"></script>
 </body>
 </html>
diff --git a/qa/login-slot.mjs b/qa/login-slot.mjs
new file mode 100644
index 0000000..49ddd84
--- /dev/null
+++ b/qa/login-slot.mjs
@@ -0,0 +1,42 @@
+// Login ads are a flat 30-day slot, not a daily meter.
+//
+// The old model charged 100 credits for every day a campaign was shown, with no end date.
+// That produced 74-day queues, and every new campaign added 100/day of charges while adding
+// no inventory — on 18 Sep, 15 campaigns were charged 1,500 credits against a platform that
+// had produced 367 login impressions in its whole life.
+import { createRequire } from 'node:module';
+const require = createRequire(import.meta.url);
+const ads = require('../ads.js');
+
+const ok = [], bad = [];
+const t = (n, c, extra) => { (c ? ok : bad).push(n + (c || !extra ? '' : '  -> ' + extra)); };
+
+const r = ads.rates();
+t('a slot price is configured', Number(r.loginSlotCredits) > 0, String(r.loginSlotCredits));
+t('a slot length is configured', Number(r.loginSlotDays) > 0, String(r.loginSlotDays));
+t('the slot is 3,000 credits for 30 days', r.loginSlotCredits === 3000 && r.loginSlotDays === 30,
+  r.loginSlotCredits + ' / ' + r.loginSlotDays);
+
+// the price matches what 30 days used to cost, so nobody pays more than before
+t('same total as 30 days at the old daily rate',
+  r.loginSlotCredits === 30 * r.loginCreditsPerDay,
+  r.loginSlotCredits + ' vs ' + (30 * r.loginCreditsPerDay));
+
+// the source guarantees that matter, checked directly — these are the behaviours that stop
+// a slot draining against days when the gate produced nothing
+const src = require('fs').readFileSync(new URL('../ads.js', import.meta.url), 'utf8');
+
+t('buying a slot charges the whole price up front',
+  /Login-ad slot \(/.test(src) && /chargeCredits\(campaign\.id, v\.c\.budget, 'Login-ad slot/.test(src));
+t('a slot gets an end date at purchase',
+  /out\.expires = Date\.now\(\) \+ days \* 86400000/.test(src));
+t('the MySQL daily meter skips slot campaigns',
+  /expires IS NULL AND \(last_day_charged/.test(src));
+t('the JSON daily meter skips slot campaigns',
+  /if \(c\.expires\) continue; \/\/ slot buy/.test(src));
+t('a short budget is refused with the slot price named',
+  /A login-ad slot is ' \+ cost \+ ' credits for ' \+ days \+ ' days/.test(src));
+
+console.log('PASS ' + ok.length);
+for (const b of bad) console.log('FAIL ' + b);
+process.exit(bad.length ? 1 : 0);