If, like me, you can remember a time when not everybody in Spain had a mobile, you will also remember that there used to be just two networks, Movistar, and, oh dear, memory fails me, the Other One. Now, at that time, you could tell from the prefix three digits, which network someone else was on, and you knew that if it was the Other One, it would cost a lot more to call than if they were also on Movistar. Thankfully, everyone was on Movistar, so it was really rather simple.
Things have changed somewhat since then, and this may sound silly to all those of you who are tariff-savvy, do your research thoroughly, sign up for all the friends-and-family deals etc etc., but to a dimwit like me, it came as a bit of a shock to realise that since my most-called buddy switched from Movistar to Orange recently (on the advice of a 3rd party who was already on Orange and presumably wanted to reduce her call costs to buddy No.1), the cost of a typical 3 minute call has gone up from about 24 cents to about 1 euro. My buddy still has the same number, so I would have remained blissfully unaware of this had it not been for the fact that I hardly call any other numbers, and yet my monthly bill seems to have increased substantially. So I actually checked my bill, which I never bothered to do before!
Just thought I'd bring this to everyone's attention, although you probably all know this already?