It's a common mistake that marketing managers make: posting the same thing at the same time across all of an organization's social media channels. It's an easy mistake to fall into — time is limited and so is the budget. You want to maximize sales with a minimum of resource expenditure.

But posting the same messaging across all channels is like shouting into a loudspeaker. Not only does it sound canned to savvy users who are connected over various sites, it can be counter-productive, or even make your brand seem tone-deaf. After all, people use various social media as vectors for different types of information-gathering or engagement. All sites aren't created equal.

The Facebook-Twitter-Instagram link-a-bot.

It's hard to pin down the exact portion of Facebook users who also use Twitter, Instagram, et al. There are, assuredly, many. Facebook still has them all beat on sheer numbers of users and may arguably be the most diversified audience. But each outlet has its own purpose. Here's an hypothetical:

A 30-something guy who has a Facebook profile for friends and family and a separate Twitter account for news and interesting information. He's artsy; he has an Instagram account on which he takes photographs of interesting or ironic scenes he finds just walking about in his daily life. And by day, he's a professional designer, so he's on LinkedIn to network with other creatives, ad agencies and design shops.

Here's the rub: he follows Musician X, who has a Facebook, Twitter and Instagram presence. But all that musician's social media strategist (because, let's face it, our hero has no illusions about how things work) always posts the same update simultaneously across all the musician's platforms. In fact, she has all the accounts linked together through HootSuite, so that she can click one button to post to all three.

Our user uses each channel for a purpose, and he now knows he can unfollow Musician X on Facebook and Instagram because Twitter is all he needs to keep interested. Moral of the story? The social media manager is missing out on multiple opportunities for engagement.

Who uses which channels?

As we mentioned, Facebook is a general hodgepodge. You can break out by segments and reach out to particular interest groups — that's the genius of getting everyone to tell you his or her "likes" up front — but the theme is comparatively loose.

On Pinterest, though, the theme is visual. And it's overwhelmingly female. It's overwhelmingly female in the 18-45 age demographic. So you'll want to match this audience up to your marketing prism data: how would you speak with an 18 to 45-year-old female? What motivates her? What are her concerns? What are her interests?

On LinkedIn, you're speaking strictly to the professional crowd. You can post up and share now — just like Facebook — but it's all business. No loose talk. Proper. Formal. Branded.

Twitter is highly popular with younger uses and with the tech-savvy. Let's say you want to reach out to people with political interests. You wouldn't want to target middle-aged to senior-aged people with political interests on Twitter; they're largely not there. Try Facebook instead. But you will get younger people who are extraordinarily engaged with the political world. And you need to craft your message in their language.

Know your audience before you post. Then craft accordingly.

Do your research. It's possible to save time, meet your budget and increase your sales using a multi-vectored social media marketing approach, but make sure your organization doesn't come out of the gate sounding like a link-a-bot. Let what you want to say — and who you want to reach — determine where you post. Tweak your message to appeal to the segments using each channel and you can rise above the noise.