How are the ads that FB pushes into your feed not spam? Seems more or less indistinguishable too me
Like them or don't, but the ads on FB are not spam because they are not unsolicited and are targeted.
If there was a plain choice between without ads and with (probably at different prices), I could accept them as a transaction I have accepted. But such choices are often not available, they are bundled in with a bunch of other choices.