This is a great question and the answer varies some depending on what you're selling, but here is what has always worked the best for me:

1. Offer free, tangible value in some form (articles, videos, tools, resources, etc) 2. Do number one to such a degree, that you and maybe others feel like you should be charging for what you're doing/providing 3. When you find something that hits (and its gaining a decent amount of attention) find a way to charge for a fuller, larger, more expansive version of it (better features, an in-depth class, 1-on-1 coaching, a white glove service) 4. Repeat and scale

This is very much a birds-eye-view, takes a lot of time, and varies greatly between B2C and B2B/physical products vs services. But the general idea remains the same.

The reason so much advertising feels slimy is because in many cases, it is. It's a company buying your attention and offering very little (or often nothing) in exchange for that attention.

If you do this enough it will "work" to some degree, but it's largely a volume game.

But if you're willing to invest the time, and deliver value both through free means and eventually paid; it's nearly always a much better long term strategy.