IN DEFENCE OF CHUGGERS 
I used to work as one. The company was paid a fixed fee by the charity to raise £X, so any costs incurred wouldn't go up for the charity if we had a bad day or whatever. I was on about £8 an hour which was good for back then.
However - when I did it, it was a fairly new thing and people were I think more receptive to it.
Factoid 1 - it is the most cost-efficient way of raising revenue for a charity, much more so than mailshots which have really low returns, tv ads, billboards and charity shops. Yes they are paid, but charities employ lots of people in different capacities!
Factoid 2 - our target was to sign up 3 people a day. That is a helluva lot of rejection, and the abuse you get from the public reduces you to tears frequently. Spitting, shoving, verbally abusing, sexually harassing...
Factoid 3 - we received training and info about every charity we fundraised for, often getting to visit their centres and see them at work, to motivate us. We genuinely did care and the buzz of signing someone up was amazing.
Factoid 4 - we were very strictly trained never to harass people. The stories on here make me
we would have been disciplined if not sacked for speaking to the public like that! We were constantly told not to guilt-trip, and always accept the first 'no'.