Oh gosh, how terrible, I shall call the rspca at once!! ;)
They tried that business model and for one reason or another the sums didn't work out. It was either from the advertising budget to sell other services, subsidised by profit from paid subs (although with google et al able to offer very cheap space thats a tough market) or just money to grow market share or a combination, it just didn't make sense. They have given warning and you can transfer to another provider. Theres plenty of them around, it's easy to pickup 5gb for free, you can even get 50gb for free from a few places. Owncloud is another option, either on your home pc if you are happy securing that otherwise a VM or a VPS would be another way.
It will be interesting to see if any of the major cloud providers jump on this, if they have any sense they will offer a gratis migration service for the data to help capture the refugees. It shouldn't be too hard to figure out.
I wonder what this will mean long term. MS \ Google will probably have a 'free' (at the point of use) tier for a hell of a long time if not forever but what it will mean for box \ dropbox \ tresorit etc will be interesting to find out. Dropbox probably has enough momentum and paid subs. The rest may go the same way.