"If it paid well" externalizes the ills it inflicts on other people. And they matter, too.
Hurting others unnecessarily is the only sin in the world. Don't ever, ever be That Guy.
Nobody is 'hurting anyone' - not even slightly, by ensuring that their free product also has ads.
If ads are unscrupulous, or if the company is doing shady things otherwise, then yes - bad.
But there is no moral argument against making sure that decent ads work with a free product, or when ads are part of any product wherein the social contract is to that expectation.
Facebook has ads, just like CNN and Cosmopolitan, that's normal, ethical, and within the expectations for user's experience. Again, shady things notwithstanding.
In 2018, people can pay or see ads, or a combination of both, there is no pragmatic way around this, and too many decent products depend upon ads for their existence, that's where we are until someone comes up with something better.
This isn't a convincing argument. As an extreme example, replace ads with something that's clearly detrimental for the user: "nobody is hurting anyone by ensuring that their free product also delivers a LD50 of cyanide" is clearly bogus. While ads don't kill people, the way that they are distributed currently has many negative externalities that the user must deal with.
I'm not down with your logic.
The vast, vast majority of ads are just fine and have no negative externalities.
Most 'food' is fine, but you can gorge yourself to death.
Cars are ok as well, even though they cause death.
More like "ads are bad" means that your free product with ads is also bad, just as "cyanide is bad" makes your free product laced with cyanide bad.
> The vast, vast majority of ads are just fine and have no negative externalities.
The problem is that bad ads show up basically everywhere. Sure, 99% of the ads on news websites can't infect me with malware, but there's that one that Google hasn't gotten around to banning yet that is running on every website…and even if this wasn't true, basically 100% of them track me or make my web browsing experience slower.