I don't know. I wouldn't mind 70p for each spam call I received.
In fact, if you're a spammer, my number is 0151 HOT CASH and I'm interested in offers and deals including but not restricted to, free central heating boilers, government sponsored energy efficient replacement windows, fitted kitchens, PPI claims, accidents I may have forgotten about (well how should I know? I've forgotten!), deafness caused at work (why are you phoning deaf people?) and any sort of internet/Microsoft help you can easily proffer.
Please have your credit card details ready when you call as I'm sure you don't want to waste your valuable time faffing about trying to find your wallet. Better yet why not email me your card number and that little 3 digit one off the back and I'll set you up with an account in advance.