The offering trumps EE, which currently offers a six-month trial of Apple Music with "free" streaming data. Three's roster of zero-rated services, however, pales in comparison to Vodafone. In early November, the network operator will launch five paid data "Passes." The most alluring is the Video Pass, which costs £7 per month and gives you "free" data for Netflix, Amazon Prime Video, YouTube, Vevo, My5 and TV Player. The Music Pass, which costs £5 per month, is also notable as it bundles Spotify, Apple Music, Tidal, Deezer, Amazon Music, Soundcloud and Napster.

Zero-rated services are controversial. Critics argue that the concept fundamentally undermines the principles of net neutrality; that all data should be treated equally. If a service is "free" to access, customers are more likely to use it, regardless of whether the competition is better. That poses a problem for startups who could have great features or ideas, but don't have the cash to "buy-in" to zero-rated services like their established competition. In short, the fear is that juggernaut media companies will stifle any rival before it has a chance to innovate or attract customers.

For now, though, the UK government doesn't seem to mind. (European regulators currently judge zero-rating schemes on a case-by-case basis.) Customers aren't likely to complain either, because "free" data is, well, free (provided you don't mind using the inclusive services). Unless a regulator steps in, these schemes will only grow in number — especially as carriers try to wean their subscribers off high and unlimited data cap plans.