Re: Cheap at the price
"Do they have millions of business customers paying idiotic amounts or something?"
Have had for years.
Vodafone also have an interesting and longstanding policy on tax efficiencies. You've heard of 'revolving doors', right? And 'networking', and 'tunneling'? Well for a long time there's been a network tunnel between HMRC and Vodafone, but it's one way rather than two way: senior HMRC officials dealing with corporate tax get very senior jobs at or near Vodafone dealing with corporate tax.
E.g. top taxman Dave Hartnett moved from HMG to Deloitte (Vodafone's favourite tax-prevention outfit) in 2013, several years previously (2007) John Connors had moved directly from HMRC to Vodafone's top in-house tax-prevention job.
Nice work if you can get it.