Free services funded by ads have been a boon for the poor.
For any given ad supported service, one of two things must be true:
(1) the ad spend was more than or equal to the cost of the service for those users
(2) the ad spend was less than the cost of the service for those users
From fork (2), it follows that the service isn't sustainable anyway.
From fork (1), it follows that the buyers of the ad slots in turn only make a profit if those ads led to sales higher than the ad spend.
But for any given poor person, buying that which was advertised on the ad supported service necessarily means spending more than they would have on a non-ad-supported version of the same ad supported services.
thinking of stuff like facebook here...
Endless investing is, depending how you look at it, either not (just) ad supported and preceeds the premise, or it still is ad supported (and hence (1)) just with extra steps to badly hide who is doing it.
Hmm… I suppose the purchase of a vote in a democracy is something that a poor person might not otherwise be able to sell, and where "we advertised and convinced you" is (depending on campaign finance etc. rules) one of the legitimate ways to do it… but even then, for reasons too long to type on my phone, I'd say in this case it would still make the poor poorer.
It doesn't matter how much you think my attention is "really worth". If I want the service now, have no cash, but can pay with my attention, I am strictly more enabled than if the service only accepts cash.
The fork between (1), (2) is how much cash their attention is actually turned into.
To put it another way: what's the attention of a poor person really worth, in dollars? Answer is always less than or equal to the amount they can spend.