To put it bluntly, Weedmaps is no joke. The Yelp of marijuana dispensaries has grown to $30 million in yearly revenue, and now it’s saying “High, NYC” with a Times Square jumbotron campaign to legalize pot. For the next 60 days, an 8-second Weedmaps ad will blaze across the CBS Super Screen pointing New Yorkers to a site of legalization resources and a petition. *420, advocate it*

Weedmaps sprouted back in 2008 to help people find where to buy legal cheeba. Not only does it sniff out what to smoke, but by promoting pricing transparency, it creates competition that burns down the cost per eighth for consumers.

Since then it was bought by a public company, which helped it roll up community site Marijuana.com for $4.20 million and dispensary point-of-sale system MMJmenu in a series of acquisitions. But after bogarting it for two years, General Cannabis Inc (renamed SearchCore by a bunch of squares) passed Weedmaps back to its original founders.

Suggested soundtrack.

With nuggets now legal in Colorado and Washington, and 20 states chill about enchanted broccoli for medical use, Weedmaps’ business is blossoming. It charges thousands of sinsimilla shops and dank delivery services to list their reviews. MMJmenu supports 900 dispensaries, and ganja Groupon clone Weedmaps Deals is pulling in about $250,000 a month. Soon it plans to pack head shops, hydroponic stores, vaporizers and more into Weedmaps.com

Today it’s aiming to bake its name into people’s brains in new markets like New York, where medicinal marijuana is expected to get the green light in 2014 and recreational pot could be legalized in a few years.

“The fewer people suffering under marijuana prohibition the better,” co-founder and CEO Justin Hartfield tells me. “We wanted to educate New Yorkers and get our brand out their proactively. This is the first time Weedmaps has marketed to the mainstream.”

The ads light the way to resource site Weedmaps.com/nyc, which praises champions of legalization and chides the narcs who oppose it. Like a digitized version of that bloodshot-eyed pot enthusiast you knew in high school, the page also pushes a petition for pot law reform, a goofy guide to the best local smoke spots and links to educational articles about Reefer Madness.

If pot law reform gives you a rush, check out Marijuana Majority, a site aimed at galvanizing support for legalization from policy makers and celebrities.

Some worry their friendly neighborhood dealer will see their livelihoods turned to ashes wherever weed becomes legal. That’s not just paranoia, says Hartfield. “It’s going to be corporatized, professionalized, and the amateur players are going to be pushed out.” Still, legalization will keep people out of a criminal justice system that burns taxpayer dollars, create huge new business opportunities, and make weed safer.

For example, there’s a new high-tech way to smoke known as “dabs.” Incredibly potent butane hash oil with a much higher THC content than marijuana is dabbed onto a titanium nail heated with a blowtorch to produce smoke. The problem is that making dabs in secret due to prohibition is dangerous. It requires running liquid butane over marijuana to extract the psychoactive elements. Without regulated safety precautions, butane explosions have occurred. And if butane isn’t fully boiled out of the hash oil before it’s smoked, it can be hazardous.

So while Weedmaps has much to gain financially from legalization, it’s also trying to make the world a safer place for stoners.