Digging a little deeper, the fact that 10% of forwarded emails are sponsored[0] highlights another major issue with advertising - the conflict of interest between user needs and site operator's profit. How do I know which emails I can trust as having useful unbiased information (i.e. satisfying my needs), and which are potentially misleading junk adverts (i.e. satisfying the site operator's desire for profit)? And what is to stop the signal to noise ratio becoming completely untenable over time in the desire to maximise profit?
I'm not completely anti-advertising BTW - there is a time and place for it. Just not when you are trying to use informational sites on the web. The analogy I've used is that you don't want annoying salespeople in a library getting between you and your books, but you don't mind them so much when you are down the high street shopping.
[0] https://silken-cafe-474.notion.site/About-The-Sample-a989b5b...