Mozilla has announced a study where Firefox will promote the ProtonVPN service as a new revenue source. The service will be recommended when visiting VPN provider sites, streaming services, or when connecting to insecure wireless gateways. Mozilla is performing this study to test a new method of generating revenue for the organization. A portion of these proceeds will be shared with Proton VPN, to offset their costs in operating the service, and a portion will go to Mozilla. While it is important that Mozilla creates new revenue streams, some may find it too aggressive to target VPN providers for the promotion.
Source: https://www.bleepingcomputer.com/news/software/firefox-targeting-competing-vpn-sites-with-protonvpn-offer-in-new-test/