Have you ever received a request to connect on LinkedIn from someone you didn’t know or couldn’t remember?

A few weeks ago, Josh Turner encountered this situation. The online request to connect came from a businessman on the opposite coast of the United States. It came with a short introduction that ended with “Let’s go Blues!” a reference to Turner’s favorite hockey team in St. Louis that he had mentioned in his profile. “It was a personal connection … that’s building rapport.”

LinkedIn is known for being the professional social network where members expect you to keep buttoned-down behavior and network online like you would at a business event. With more than 200 million registered users, the site facilitates interaction as a way to boost your stature, gain a potential customer or rub elbows with a future boss.

But unlike most other social networking sites, LinkedIn is all about business — and you need to take special care that you act accordingly. As in any workplace, the right amount of personal information sharing could be the foot in the door, say experts. The wrong amount could slam it closed.

“Anyone in business needs a professional online presence,’’ says Vanessa McGovern, the VP of Business Development for the Global Institute for Travel Entrepreneurs and a consultant to business owners on how to use LinkedIn. But they should also heed LinkedIn etiquette or risk sending the wrong messages.

One of the biggest mistakes, McGovern says is getting too personal — or not personal enough.

Sending a request to connect blindly equates to cold calling and likely will lead nowhere. Instead, it should come with a personal note, an explanation of who you are, where you met, or how the connection can benefit both parties, McGovern explains.

Your profile should get a little personal, too, she says. “Talk about yourself in the first person and add a personal flair — your goals, your passion … make yourself seem human.”

Beyond that, keep your LinkedIn posts, invitations, comments and photos professional, McGovern says.

If you had a hard day at the office or your child just won an award, you may want to share it with your personal network elsewhere — but not on LinkedIn.

“This is not Facebook. Only share what you would share at a professional networking event,” she says.

Another etiquette pitfall on LinkedIn is the hit and run — making a connection and not following up.

At least once a week, Ari Rollnick, a principal in kabookaboo, an integrated marketing agency in Coral Gables, gets a request to connect with someone on LinkedIn that he has never met or heard of before. The person will have no connections in common and share no information about why they want to build a rapport.

“I won’t accept. That’s a lost opportunity for them,” Rollnick says.

He approaches it differently. When Rollnick graduated from Emory with an MBA in 2001, he had a good idea that his classmates would excel in the business world. Now, Rollnick wanted to find out just where they went and reestablish a connection.

With a few clicks, he tracked down dozens of them on LinkedIn, requested a connection, and was back on their radar. Then came the follow-up — letting them know through emails, phone calls and posts that he was creating a two-way street for business exchange. “Rather than make that connection and disappearing , I let them know I wanted to open the door to conversation.”