Consultants and marketers have historically been fond of the strategic perspective and for good reason: if you don't know where you are going, then any road will take you there.
In fact I agree that businesses should not embrace social media unless they have a good reason for it.
But there seems to be a catch. Once you start down the social media road, situations change and you may find that in pursuit of one goal a more valuable one emerges. You may also find that in the fast interaction of day-to-day business the real power of each social media tool you use may be in tactical implementation.
The strategy of a telephone may be to ensure customer communications. But one day your kid may call you to say she or he just got admitted into college. That is off-strategy, but my guess is that you won't tell your kid to get off the phone because this is an inappropriate use of the tool.
When I wrote Twitterville, more often than not, business people told me they started using the tool for one reason and a better one just popped up. Lionel Menchaca at Dell wanted to drive traffic to his blog. It worked, but he found greater value in the content relevant to his company he found there and the speed of conversations.
IBM started using Twitter ad hoc and discovered it was the best place to demonstrate the expertise of employees and a faster, better way for its ecosystem to communicate than its own Lotus Notes. Mayo Clinic started a Twitter account to stop the sort of brand ID theft it had experienced on MySpace and discovered it was a great venue for discussing health issues.
Social media's greatest benefit over other options is that it is both interactive and public. You may start a conversation and someone talks back. You may join a conversation and find something valuable to add to it. You may talk about lunch or weather and end up doing business.
When you start, you just don't know where it will take you.
When Laura Fitton started, she was a stay-at-home mom who hungered for interesting conversation with grown ups. I doubt she had any sense that it would help her become an author, speaker and entrepreneur.
Sometimes the path has many switchbacks.
United Linen, a restaurant uniform and laundry service started tweeting Bartlesville Oklahoma high school baseball scores to be a hometown booster. They eventually posted a series of YouTube videos on different ways to fold linen dinner napkins making them a thought leader in a vertical niche. Eventually they would use Twitter to update customers during an ice storm. The latter incident would indicate an emergency preparedness strategy, but my impression is that it was a much more tactical implementation. Something happened and Twitter was a tool at hand. The phones were down and Twitter was working, plus it was faster and easier.
My point is to go into social media with a sense of who you want to reach and why. But be prepared for surprises and pack flexibility into your approach. Surprises happen and social media allows you to adapt and adjust with greater ease, less time and lower cost than other available options.