Kyra Wilson, an artist living in rural Vermont, had just joined Facebook in summer 2009 when she began seeing posts from friends about their activities in some farming game. Harvesting crops. Asking for materials to build stuff. Leaving virtual gifts.

Curious, she joined "FarmVille" to see what all the fuss was about. Three year later, she hasn't stopped playing.

"There was just something compelling about the fact that you could feel -- this is going to sound strange -- productive," said Wilson, 37, who spends about five or 10 minutes each day playing. "You start out with one or two plots and then you figure out the game. Besides, you can't work all the time. You need some sort of fun outlet. This is something good I can plug into and relax."

Call it a hobby. Call it a video game. Or, as some critics do, call it an addictive time waster. Whatever you call it, it's clear that as "FarmVille" celebrates its third anniversary this month it has had an impact that nobody could have foreseen when it launched June 19, 2009.

By becoming social gaming's first monster hit, "FarmVille" legitimized an industry by finding a way to attract millions of people who had never played games. It sent shock waves through the ranks of traditional video-game makers, and it launched a little-known startup, Zynga, on a path to becoming a billion-dollar public company. Most surprising of all, though, may be the enduring popularity of "FarmVille," remaining one of the top Facebook games even as most social games tend to rise and fall quickly. In the face of this success, I wonder: Is it time to give "FarmVille" its due? Among current video games, its impact might only be matched by the success of "Angry Birds" on smartphones.

Though there might be some hyperbole here, Zynga Chief Operating Officer John Schappert argues -- and I agree -- that this innocent little game deserves a place among the iconic video games of all time, ones like "Pong" and "Pac-Man."

Is he right?

In the beginning

On the day "FarmVille" launched, Cadir Lee, Zynga's chief technology officer, thought he was prepared. Zynga, just one of several social gaming startups, had about 150 employees, including a small team who had built "FarmVille" over just a few weeks.

Companies like Zynga focused on building games to play on Facebook, and the most successful at the time had attracted between 4 million to 5 million daily average players. Lee figured "FarmVille" had a good shot at that.

But when the game launched, the number of players began ticking up at a rate he couldn't believe. Zynga employees had a tradition of wearing red shirts when a game passed a "million milestone," and many found themselves donning red day after day.

Lee recruited other Zynga employees to help keep it running while pulling all-nighters to configure new servers and write software to handle the traffic. After six weeks, the game had hit 10 million daily average players.

"It was like your world shifted," Lee said. "Like when you discovered the world is not flat. It was that kind of feeling for the company."

"FarmVille" continued to grow, to 25 million daily average players after six months. In the process, it became a pop-culture phenomenon. Facebook news feeds soon became jam-packed with posts about players' progress and requests for help building their farms. Traditional gamers derided it as a mindless, "no fun" game.

Ian Bogost, a video game designer and a professor at the Georgia Institute of Technology, criticized the emptiness of social games by creating a parody of "FarmVille" called "Cow Clicker" in which a player simply clicks on a cow in Facebook over and over.

But "FarmVille" clearly stuck a chord with a mainstream audience, bringing in millions who had never played a video game. Todd Arnold, then working at Electronics Arts and now Zynga's senior vice president of games overseeing "FarmVille," saw an incredible opportunity.

"I came to the realization that in an almost 20-year career in console and PC games, the titles I worked on sold a total of probably 25 million copies," he said. "It was the same number of people playing 'FarmVille' in a day."

In research and conversations, players revealed several motivations for playing. They liked achieving small goals, communicating with friends, cooperating rather than competing, and decorating their farms.

That's why Wilson, the Vermont artist, continues to play. For her, it's a hobby, something to do during a coffee break. But she has also met numerous friends through the game, including one who's driving up to visit from Maryland in the summer. And as an artist, she enjoys the visual expressions the game allows.

"I like to decorate and design the farm," Wilson said. "It's like a little diorama for adults."

Eventually, casual players dropped off, but the most passionate players stuck around. Even at these lower numbers, "FarmVille" never dropped out of the top 10 Facebook games. Other social games came and went, but "FarmVille" endured.

"The fact that it's going so strongly after all these years is sort of the exception that proves the rule," said Sean McGowan, an analyst with Needham & Co. "The idea that it's still going this strong for this long, that's everyone's goal. It's the Holy Grail. But it's very rare."

This dynamic -- fewer but more passionate players -- created another surprise: Zynga's revenue from "FarmVille" continued to grow. Zynga games are all free to play; the company sells virtual goods to players and runs ads.

According to Zynga's securities filings, on average about 1.9 percent of all players spend money in Zynga games. But as the number of "FarmVille" players decreased, the percentage of players who spent money on the game increased (though Zynga won't say what the actual percentage is now).

In the most recent quarter, when revenue from online games increased by $62.9 million, $24.2 million of that gain came from "FarmVille." Overall, it accounted for 29 percent of Zynga's online gaming revenue of $292.8 million last quarter, up from 27 percent for the same period a year ago. "CityVille" was second at 17 percent.

Expanding the game

A few years ago, Zynga began thinking about ways to extend the life of "FarmVille." The company maintains a large studio dedicated solely to the game.

After lots of conversations with players, the company introduced its first "expansions" in March 2011, an "English Countryside" that allowed players to create a new farm using British-themed crops and goods.

The company has now rolled out five expansions, including the most recent one last week, "Jade Falls," which features Asian-themed crops and characters.

So far, these expansions have kept "FarmVille" growing. Still, I wonder: How long can Zynga keep the phenomenon going?

"You're not thinking one month out, two months out," said Jason Brown, Zynga's vice president of player insights. "It's something people think of as a hobby, like knitting or gardening. So you have to think about running it in perpetuity.

"Really, you're planning on a forever game."

Contact Chris O'Brien at 415-298-0207 or cobrien@mercurynews.com. Follow him at Twitter.com/obrien and read his blog posts at www.siliconbeat.com.

HARVEST TIME

Here are a few things that might surprise you about "FarmVille":

1. The game was launched June 19, 2009.
2. It peaked with 32 million daily players in March 2010.
3. It has always been among the top 10 games on Facebook since its launch.
4. Revenue from "FarmVille" represented 29 percent of Zynga's online gaming revenue last quarter, up from 27 percent the same quarter a year ago.
5. "FarmVille" has 14,000 unique items in the game.
6. Since "FarmVille" first launched, Zynga has introduced 130 new features in the game.
7. "FarmVille" players have created over 5 billion farm plots.

Source: Zynga; SEC filings