This would also imply that the best thing ethically is not to give people goods in exchange for labor because the simple act of interaction with them puts their housing and food needs under your responsibility.

This kind of situation is win-win-win.

The plumbing website makes money from the ad - supporting their operations so plumbers can keep a good source of plumbing educational content.

The SaaS company gets to put their product in front of users to look at and consider buying.

The users get to see a potential product with no obligation that they may have not ever heard of before.

If you remove approved commercial options for promoting yourself, like advertisements, then most of the other options left for promotion are essentially spam.

If your answer is word of mouth, that's naïve. I've worked with over 100 startups at very various stages of marketing in the last 15 years. Word of mouth is fire in a pan. It is very industry dependent, context dependent, and company dependent.

In the "advertising led" model of customer discovery, businesses advertise to essentially tell the market that they exist and provide a service. They do so by paying for advertising space across various mediums. This includes everything from their store signage to Craigslist ads, to TV and sophisticated digital advertising.

Most modern advertising is an auction where businesses compete to serve their message to customers the algorithms think are most likely to be interested.

This function - of matching users that might be interested in products to businesses providing products - is at this point hugely scaled.

People who want to ban ads will usually give the alternative of a reviewed directory of products and services for each category. That, they say, would be the ideal method of product discovery, along with word of mouth.

However, that runs immediately into the same problem that communism has historically. Who actually controls these directories, which would be a huge source of power for society? I posit that that it is impossible to centralize this effectively, and that the most likely most effective method for idea and product dispersal is something close to modern marketing and advertising.

He aggressively promoted and marketed himself!

Biggest example: Going on Letterman and other corporate talk shows / interviews (he went on Letterman 12 times to promote himself, not making much money, purely for driving awareness - classic pr marketing technique that he used repeatedly)

He also went far beyond live acts when he started monetizing his recorded acts that were playing/distributing through corporate partners. Those recordings and specials were heavily marketed and he benefited from it because it created scale.