(CNN) California began selling recreational marijuana Monday in what's seen as a milestone in the mainstreaming of the weed, and hundreds lined up to buy it.

Lines formed outside stores licensed to sell the drug long before opening hours, and store owners said they had stocked up in expectation of huge demand.

"It is probably our busiest day in our seven-year history," said Matt Lucero, the owner of Buddy's, a dispenser of medical-use marijuana in San Jose that holds the first license issued by California to also sell recreational marijuana. "We have folks outside; every chair in the building is filled right now."

At Harborside dispensary in Oakland, hundreds lined up to be the first to buy the legal weed, CNN affiliate KGO reported

Speaking with CNN, Lucerno said he expected a 30% bump in sales overnight, but "it looks, in looking around this room, more like 50 to 60%."

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