Vadim Filin

Proton VPN got caught running price sensitivity tests on its own users, then told everyone it was a stale sale. Here's what happened. People on Proton's subreddit noticed they were being quoted different prices for the same plan. Refresh the pricing page and VPN Plus shows $2.77/mo at 72% off. Open a fresh incognito window and it's $3.23/mo at 68% off. Same plan, same country, same second. Nothing about the visitor changed. Proton VPN's General Manager replied that there was no adaptive pricing, that a sale had recently ended, and that the intro prices hadn't "universally refreshed." He called the low numbers an error and suggested people grab them before they got fixed. Then Windscribe pulled the page source. Every visitor is being sorted into a variant, and the test is labeled in plain text inside an HTML meta tag: ab-test:VpnHpAndPricingVpnPlusSensibility300726. One session returns content="A", the other returns content="B". Two separate pricing URLs, one normal and one flagged test-300726-b. A screen recording shows the price flipping between clean incognito sessions, $3.49 at 65% off, then $2.99 at 70% off. Expired sales don't do that. Cached pages don't do that. Cloudflare has never once injected a named A/B test into anyone's markup. Worth being precise about the wording, because Proton was. Adaptive pricing uses your personal data to set a number tailored to you. Price sensitivity testing quotes different people different prices for the identical product to find out how far you can push before sales drop off. The GM denied the first one. Nobody accused them of the first one. A/B testing prices is ordinary commerce. Amazon does it, airlines do it in their sleep, and almost nobody would have cared. But Proton sells privacy, and privacy is a trust product. The experiment was never the scandal. The denial was. Run the tests. Just don't call it a glitch when your own code is holding a sign with the test's name on it. Receipts: