I always wonder how these £20 a year places actually make a profit. They must be banking on the fact that nothing will go wrong usually and you'll not need to talk to technical support. If my query takes up 2 hours of a technical support guys time then I've already cost the company £20 then and there.
They'll also need to have a very large number of customers to just break even for the staff alone. Then there are colocation and hardware costs.
I've nothing against Wiserhosting, I've never even heard of them before but there are a few companies that do this and I've just been curious.