The “free” or cheap VPN is collecting user data and selling it to third parties and advertisers (a very lucrative business).The VPN blasts you with ads or redirects your browser to third party websites – and then earns commissions on sales.They will simply cancel your “lifetime” subscription after a year or two. The VPN is similar to a Ponzi-scheme, requiring an ever-increasing number of new subscribers to remain financially solvent.
The “lifetime” is actually referencing the lifetime of the VPN company – not the customer. After selling a large amount of lifetime subscriptions, the owners could simply pay themselves out and then close the business.
Some VPNs are now cancelling all “lifetime subscriptions” and converting these accounts to recurring paid subscriptions. Here is one example I found from VPNLand: