Those who say all marketing = lying are wrong.
Really good marketing is understanding who your perfect customers are, finding out what they want, and offering it to them in such a way as they buy it. No deception involved.
If all you're doing is pandering to people's weaknesses and selling them quick fixes that don't work, that's fraud (by the dictionary definition of "deceit, trickery, sharp practice, or breach of confidence, perpetrated for profit or to gain some unfair or dishonest advantage")
Now, if you make your money scamming idiots, maybe they deserve to be scammed in your eyes. They'd probably just spend it booze or junk food anywaym right? However you want to square it with yourself is up to you, but don't be so self-deceiving as to claim it's ok because everyone in marketing does it.