This blog post originally appeared at the Harvard Business Review.

Millions are in uproar in #Cairo. Rumor is they heard our new spring collection is now available online at http://bit.ly/KCairo – KC

With these 132 characters, designer Kenneth Cole unleashed a worldwide revolt: not against the Egyptian regime, but against the ill-advised use of Twitter. The tweet generated an immediate backlash from social media observers, marketing professionals and fashion bloggers, making Cole an instant poster boy for social media PR gone horribly wrong.

Cole’s tweet is more than a cautionary tale about the importance of attending to the boundary between engaging edgy and offensively tasteless. After all, marketers tread back and forth across that line all the time, and it’s a win some, lose some game.

But Cole’s real transgression wasn’t 132 characters long, it was just one: #. By including #Cairo in the tweet — as opposed to simply referring to “Cairo” — Cole inserted an ad into a conversation and news stream that millions of people are following, and many Egyptians are depending on.

That # denotes a Twitter hashtag: a convention that’s used to organize thematic conversations in Twitter. During any global crisis or event, from the Haitian earthquake to the Oscars, you’ll find a Twitter hashtag (or several) used to include relevant tweets in the emergent conversation.

Unfortunately, spamming Twitter hashtags with unrelated tweets is nothing new. U.K. retailer Habitat has already learned its lesson about the perils of misappropriating hashtags as a marketing tool. Now Cole is learning the same lesson, but it’s one with implications that go beyond how social media marketers use Twitter.

Marketers need to recognize that a social media presence is not a billboard: it’s not an empty space that you can buy and slap your message on. When you engage in a social media campaign, you’re joining a conversation — or in Cole’s case, crashing a party to which you have not been invited.

Imagine walking into a cocktail party, pushing yourself into a knot of people talking about their Christmas plans, and abruptly changing the subject to SUV models. Or more accurately, imagine walking into an AA meeting, and interrupting someone’s recovery story with an announcement about your upcoming sofa sale. Or worse yet, imagine joining the AA group, spending three months pretending to be an alcoholic, and then pitching the rest of your group on your Amway products. Classy, right?

That’s exactly what marketers do when they charge into a hashtag, Facebook group, or any other kind of online community or conversation. These web spaces aren’t invitations to sell: they are invitations to connect.

Smart marketers find a way for their social media efforts to support that connection; to not only respect the conversation that is already underway, but to strengthen and extend it with their own contributions and resources.

Tone-deaf marketers … well, Kenneth Cole has showed us just what they do.