GiffGaff was originally a Telefonica experiment to see if a Self Support, web based MVNO would work, and then it exploded and Telefonica have kept it running since..
o2 did this with the Genie brand as well
Current Phone: Sony XPeria Pro-I and Motorola Razr 5G I also have a Planet Computers Gemini
I work in IT as an Enterprise Messaging and Collaboration Tools Administrator (Office 365, Slack and much much more) and manage hardware both Mobile and Desktop / laptop, my desk is a bit like PC World
-- We are all customers and dont have access to any o2 accounts