In my country, and probably elsewhere, there are two types of people who collect for charities in public. The first are either employed by the organisation, or (more commonly) volunteer for it. They genuinely care about the cause, but tend not to be pushy and express genuine gratitude for every donation they get.

The second kind are employees of direct marketing companies which have contracts with charitable organisations. These people receive commissions on signing people up for ongoing donations. They refer to signing someone up as a "sale", call themselves salespeople, and will use any trick at their disposal to sign you up. They study pamphlets about the charities so they can answer questions, but all they care about is getting your credit card details and getting enough monthly payments out of you to not have their commission clawed back.

If you see a job ad for a "self-starter looking for a career in sales with unlimited earning potential - no experience necessary" there's a decent chance it's for one of these companies. I worked for a company (office admin - I lasted about 4 months, and only that long because I had a family to feed) that contracted out to these companies, and the people were disgustingly unethical - they'd joke about what suckers the people they signed up were, brag about how many girls' numbers they could get out of pretending to care, and didn't care at all about what they were doing. The charity was just a product they sold.

The company I worked for also ripped off the companies they worked for. For example we had contracts with 2 different power providers to send people out door to door to offer rebates for switching providers, and for each sign-up we got a fee. We contracted this work out to 4 or 5 different companies which swapped staff freely and were all partially owned by our company. One month we'd send one company working for one provider to a given area, and within a few months we'd send another company working for the other provider to the same area, sometimes with some of the same salespeople. I have to assume the contracts and company ownership patterns were structured in such a way as to keep this legal, but fuck was it unethical. I know this is the ultra-sleazy end of the wedge, but I've never really trusted anyone in the marketing industry since.