Marketing doesn't happen only when the marketer wants. It also happens when the consumer so desires.
This matters not only because of the increasingly ubiquitous conversation about so many topics (yes, including your brand) but mostly because of when and where and how those same conversations happen.
Some questions: do you know when your customers are online or do you just post as you see fit for your own daily schedule? What topics truly matter? What do they expect from you?
As it happens, according to VentureBeat, most of us are actually working based on... well, no knowledge at all. We tweet and post based on what we see fit, neglecting what actually works.
This is why often a newbie may ask the team some difficult questions such as why something is done this way and why that post came out that way. Smart marketers will have an answer based on what they verify, not what they believe. Big crucial difference.
Your community has a lot more to teach you than all you've ever read about social media marketing.