Well, they did it: Twitter has announced a business model. It's called advertising. Heard of it before? They are calling it “Promoted Tweets.” What's interesting is that the social media company (can we now call them a social marketing company?) has figured out a way to weave sponsored tweets into the fabric of the system: That is users, can essentially vote about which ads stay or go.

Sponsored Tweets will be bought and plugged into the system, clearly marked as sponsored. This will happen via the search page, where sponsors will bid for search terms, a la Google. Users can treat them like regular tweets -- for example, retweet them -- or ignore them. Posts that get sufficiently ignored will presumably go away, according to Twitter.

The initial sponsors -- Twitter calls then “innovative advertising partners” -- will include Best Buy, Bravo, Red Bull Sony Pictures, Starbucks, and Virgin America. I am quickly imagining the Twitter-scape littered with Red Bull-fueled promotion artists.

Again, the key here is that Twitter claims reall bad ads will allegedly be weeded out of the system by users if they ignore them. Obviously, the first question people will have about this system is will it corrupt the Twittersphere by introducing a flood of spam. Twitter says not, it is searching for truly viral ads -- ads that not only carry a message but are interesting to users. I clip from the Twitter announcement:

Q. What will users see?
A. You will start to see Tweets promoted by our partner advertisers called out at the top of some Twitter.com search results pages. We strongly believe that Promoted Tweets should be useful to you. We’ll attempt to measure whether the Tweets resonate with users and stop showing Promoted Tweets that don’t resonate.

Ah yes, they strongly believe that advertising should be useful. I do to. They also strongly believe in making money. They have that right. The only problem is, bad advertising on Twitter could look a lot like spam! It's certainly going to be a risk to the user community.

If you are really into this sort of thing -- paid Tweets -- and you would like to learn more about it, I would advocate reading Jeremiah Owyang's excellent summary of the new Twitter Promoted Tweets program.

Owyang points out that the new system depends on the concept of “resonation” -- that is, Twitter power users will have influence on marketing messages by retweeting them. Truly successful campaigns will “resonate” with the users and get retweeted over and over. “For Resonation, Brands Must Pay Closer Attention To Users –This Isn’t Traditional Spray And Pray,” writes Owyang.

Will it work? I suppose Twitter will start minting lots of cash. A lot of whether this angers the user community will come down to the look-and-feel of the ads and how quickly the system gets cluttered up with promotional garbage. Twitter is going to have to manage this very carefully -- or else the user community will mange it.