"I love you" is so 2009.

The newest way to send an affectionate message this Valentine's Day comes with a social media twist: "Tweet Me."

Twitter and Sweethearts candy unveiled plans this week to stamp Tweet Me on the familiar heart-shaped candy that embraced short messages long before Twitter was even a glitter.

For the 145-year-old Sweet-hearts brand, the move accelerates recent commercial tie-ins. For Twitter, it's a freebie public relations coup.

And for the nation's marketers, it's yet another savvy step into the virtual world and away from conventional advertising. The not-so-subtle message within the message: You can't even bite into Valentine's Day candy any more without getting a commercial message.

"This is an indication of the new media yet to come," says Patricia Martin, author of "Renaissance Generation: The Rise of the Cultural Consumer and What it Means to Your Business."

"It's a new way of advertising when two brands get together to create cultural meaning. That's very different from creating a 30-second TV spot."

Your odds of landing a Sweetheart candy that actually says Tweet Me: about one in 80. That's because there are 79 other phrases in use this year.

"We've always been short and sweet," says Jackie Hague, vice president of marketing at New England Confectionery, maker of the Sweethearts brand. "In this case, the technology merged with the ritual."

Sweethearts also will launch an iPhone app that sends virtual Sweethearts boxes with personalized messages that can appear on anyone's Twitter page.

"These two brands were made for each other," says brand consultant David Vinjamuri, author of "Accidental Branding: How Ordinary People Build Extraordinary Brands."

"A message in a Sweetheart has always been shorter than a tweet."

In an online survey last year, Sweethearts asked consumers to suggest the next Sweetheart candy saying, and received more than 10,000 replies. Tweet Me lapped the field. Text Me rated a distant second. Love Bug — inspired by a Jonas Brothers hit song, not the Disney movie — ranked third, Hague says.

Sweethearts executives phoned Twitter executives, and a match was made. "It's even more proof that people can say anything in short messages," says Biz Stone, co-founder of Twitter. "A 140-character message may seem short. Sweethearts are even smaller."

Tweet Me isn't the first techno phrase to zoom to the top of Sweetheart's popularity list. But most of the once-hot phrases — including Fax Me and Email Me — now seem very uncool.

Sweethearts did not have to pay Twitter anything to stamp the phrase Tweet Me on its candy, although the two companies are working in tandem on this. But Hague insists that Sweethearts isn't a commercial sellout.

"It's a recognition that society is changing the way to say I love you," she says. In fact, she says, because the phrase was the top vote-getter among consumers, "it's less commercial and more democratic."

There's one quasi-commercial phrase that won't show up on its candy this Valentine's Day: Bite Me.

In a tie-in with the "Twilight" film last spring, Sweetheart placed that key phrase from the movie and book on some candy.

But the company received complaints from some consumers. "Some thought that was a bit sexually suggestive," Hague says.