I've been hopscotching Europe this week, seeing clients and colleagues in London and Istanbul — but my thoughts have been in Los Angeles, where in a couple of weeks I'll be giving a speech called "Taking Social Media From Cool To Critical" at the 2012 Forrester Marketing Leadership Forum.

I chose that topic because it’s a concern I hear almost every day — and sure enough, I heard it from several clients on my travels this week. "We’ve put time and resources into social media marketing, because it seemed like we had to, but . . . it’s just not having much of a business impact." By comparison, four or five years into the era of search marketing, most companies were making a killing from their SEM programs. The same goes for email marketing. But here we are four or five years into the era of social media marketing — and for many companies, social media is still a curiosity, a sideshow that attracts lots of interest but adds little value. It's still cool, but at most firms, it's just not a critical part of the marketing plan.

I think the main reason marketers still struggle to make social pay is simple: They overestimate social media as a marketing tool. Let me be clear: I'm not bashing social's value for marketing; social media can have an enormous impact on the success of your marketing programs, as we’ve seen time and time again. The point I'm making is that it can’t create that success all on its own. You need to use it as merely one tool in your marketing tool kit.

I cringe every time I hear a client ask how they can build a brand with social media or drive sales with social media. Of course, social can ultimately contribute to both goals, but it's simply not very effective at taking the lead when you need to build your brand or acquire new customers. The key to success is figuring out what social can and can’t do — and then leveraging social tools where those tools excel and turning to other channels and platforms in situations where social isn’t as well adapted.

Need to create awareness from scratch? You’ll probably have a hard time doing that with a Twitter account; try reach channels like online sponsorships and offline paid media. Need to convert prospects into buyers? Facebook is going to provide limited value in reaching that objective; search and email are still your best purchase triggers. On the other hand, "owned" social platforms like blogs and communities help marketers add crucial depth to their websites, and public social presences on Facebook and Twitter can offer crucial ongoing engagement with existing customers.

The sooner we start looking at social as a valuable point solution at certain parts of the customer life cycle — rather than as something that should take over our entire marketing ecosystem — the sooner we’ll start seeing real, consistent value from social media marketing.

I’ll be talking about these ideas in much more depth in an upcoming report, in a presentation at our Marketing Leadership Forum on April 19th, and at a full-day workshop in New York on April 24th. I hope to see you at one of the events — and in the meantime, I’d love to hear your thoughts on this topic in the comments below.