Having dispatched Tu Me which is a mobile VoIPand message service of the sort already done by Skype, Viber and so on, Telefonica says it will now concentrate on its more accretive Tu Go offering which, according to a Telefonica Digital spokesperson, is not so 'over-the-top'.

Instead of offering a slightly cannibalistic VoiP service to smartphone users (subscribers to other services as well as Telefonica/O2) as did Tu Me, Tu Go is designed to live behind the mobile number and billing service and extend service reach to the other devices and networks that the user may spend part of the day on.

The idea is to enable multi-screen said the spokesperson, and to that extent it strengthens the core O2 offering. Calls or texts made from other devices will appear on the mobile phone bill.

"It required a lot of engineering and deep integration work to get [Go Tu] up and running. It was decided to concentrate resources on that, so we shut Tu Me to concentrate on Tu Go."

Indeed, the company sees the rise and fall of Tu Me almost as a necessary rite-of-passage into the brave new world of carrier-OTT services where the motto is 'live fast, die young' (or at the very least, 'keep calm and carry on').

And what of the Joyn carrier initiative for next generation messaging, which Telefonica also supports?

"We don't want all our eggs in one basket. We need to be able to move quickly and that's more difficult if there are a lot of other carriers involved."