Well, part of the awareness is because of the constant awareness campaigns by charities and the flagging up of it by people on social media. It may seem over the top and persistent, but thats what keeps it in the public consciousness

As for lining their pockets ... copying this from another comment I made a while back on the subject.

Their advertising, and our crappy £3 donations really just balance each other out (plus other overheads), and the advertising is more of a brand awareness thing. It may keep us talking about it, at least keeps it in our mind, but it's main aim is to get the charities name about as much as possible, TV, Radio, print ads etc. The more of that there is, the more high profile they are, and they need donations to do that.

Now, with that in mind, the real money comes from huge donation from big corporations and rich CEOs and the like. This is where the highly paid charity CEOs come in, their not really hired for their charity, but for their ability to wine, dine, rub elbows and generally prance around with all the people that have real money they can actually do something with. The high pay they get comes largely for the fact they are probably from the private sector originally, used to big wage, and they have the contacts to coax money out of.

They then go off to their mates at some fancy cocktail party and say, hey look, this new charity gig I got, the one you're hearing about everywhere, it could do with a healthy investment. Say £2million, and it's tax deductible, what do you say? They get a couple of them a month and they have tens of millions to spend actually helping people.