Proton VPN

Proton VPN is the VPN arm of Proton, the Swiss privacy company that started with Proton Mail. It was founded in 2014 by scientists who met at CERN, and is based in Geneva, Switzerland, which puts it under some of the strongest privacy law in the world. Its apps are fully open source and independently audited, and it runs a genuinely usable free tier — rare in this category.

The free plan has no data cap, which almost no competitor offers. Paid plans start at roughly $4 to $5 per month on a long commitment, and the Proton Unlimited bundle adds Mail, Drive, Pass, and Calendar in a single subscription.

The affiliate program is part of the wider Proton Partners Program, so you can promote the whole privacy suite rather than the VPN alone. Commission structure varies by plan: up to 100% on monthly plans, around 40% on one and two-year plans, and 30% recurring on subscription renewals.

The cookie window is a long 90 days. One practical restriction worth planning around: payouts are made by direct bank transfer only — there is no PayPal option — and the minimum threshold is $100, released monthly.