UK TV, like BBC ITV C4 and Fives, does not come any cheaper than subscription free via satellite,which is still available in many areas of Spain.
There are some areas where satellite signals have got weaker, requiring people in those areas to get larger dishes than they had to use before. But some are reluctant to have a larger dish, so they look for alternate "third party" means of receiving their TV. (Prior to 2012, in the Costa Blanca the normal sized dish for BBC ITV etc was a 1.8 or 2.4m dish, and people were happy installing them for their free UK TV channels. But people in the weaker signal areas seem to be reluctant to do this, and instead go for internet solutions - filmon (some quality issues), android boxes (faffy menus and some quality issues), mag boxes (pay for your free tv channels?).
But rememeber that the UK broadacsters have no obligation to provide live TV for expats. But there are a few EU rules. Expats in EU must have access to news and evemnts in their own language - which is why most EU countries have a fre eto air news service that covers Europe - for the UK SKy News International, and BBC WOrld News covers this.
But then soon, the EU will open up the rules a bit, for holiday makers. ie broadcasters must allow their content to be made available for their "clients" when they are in another EU country. This will have time restrictions, and is designed for holiday makers, and not permananet residents. Until the rules are changed, and all EU broadcasters buy programme rights for the whole of europe, (veyr messy to sort out), then VPNs re the only way to access content via the internet direct from the broadcasters and not a third party.