Free and benevolent maybe not. but genuine and non malicious?
"What's your business model?" "we make and sell delicious sandwiches. Customer buys the sandwich for a little mote than it costs to make so we get money for ourselves." That isn't a scam.
Correct. It's not a scam. Because it's not free. The sandwich had a price posted, you paid it, you received the product. Valid business model.
What would you think instead if you saw a NYT front page ad taken out for Free Sandwich Mart, the all-you-can-eat totally free sandwich emporium?
Or in this case, a free browser extension that paid to sponsor five thousand YouTube videos that promises to help you pay less money to every store you activate it on at no cost to you?
Does it even count if you're advertising on your own platform? If I'm able to see the "ads" in the first place, I'm already using it.
I also wouldn't exactly call a donation drive "advertising" either. They're not trying to onboard more users to the service, they're nagging people who already use the service to give them money. Which is itself leaning a bit on the wall of what is and isn't "free".