LOS ANGELES (AP) — Michelle Janikian, who writes about marijuana for publications like Herb, Playboy and Rolling Stone, says after she tells someone what she does for a living, she usually spends the rest of the conversation "trying to act so friendly and mainstream" so they don't think she's stoned.

Adam Salcido relates that after he went to work a couple of years ago for a Southern California company that helps organize weed-infused events like Hempfest and Cannabis Cup, he had to reassure his family he wouldn't turn into a drug addict.

Stoner stereotypes die hard.

But with a multibillion-do...